Appendix
3. H.? dubia (Kütz.); filament without a mucous tube; joints rather broader than long, with two puncta near each margin.
Hyalotheca? dubia, Kützing, Phycologia Germanica, p. 140 (1845); in lit. cum icone.
Nordhausen, Prussia, Kützing.
Tab. XXXV. fig. 16. portion of a filament from a drawing by Professor Kützing.
3. D. undulatum (Corda); joints with four crenatures at each margin.
Desmidium undulatum, Corda, Observations Microscopiques sur les Animalcules des eaux et des thermes de Carlsbad, p. 19. t. 4. f. 27 (1840).
Carlsbad; Prague; and Reichenberg, Corda.
The constriction of the joints is marked by slight marginal notches, on each side of which are two broad crenatures.
Desmidium undulatum appears to be a distinct species, differing from D. Swartzii by having bicrenate segments.
4. D. didymum (Corda).
Desmidium didymum, Corda, Alm. de Carlsbad 1835, p. 123. t. 4. f. 43. Kützing, Phyc. Germ. p. 141.
Carlsbad, Corda.
Ehrenberg and Meneghini unite Desmidium didymum (Corda) to D. bifidum (Ehr.), which the latter describes as a filamentous plant. Kützing removes D. bifidum to Staurastrum, but retains the present plant in Desmidium, of
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which Corda considers that both are true species. I have not seen Corda's descriptions or figures, but in a subsequent work he gives the following reasons under D. bifidum for believing them distinct: ---
"M. Ehrenberg lui adjoint l'espèce suivante, trouveé à Carlsbad. Elle en diffère totalement, du moins de celle que je considère comme la forme normale du Desmidium bifidum, qui, relativement à sa structure, principalement à la découpure de ses pointes, correspond beaucoup avec le dessin incomplet d'un membre séparé, qu' on trouve dans l' ouvrage de M. Ehrenberg, l. c. D. bifidum (bidens dans le dessin), vu latéralement, ne présente que deux pointes principales sur chaque aîle, lesquelles sont simples. Quant à l'espece suivante, nous avons dépeint deux pointes principales, très-visibles, et chacune d' elles également pourvue de deux pointes." --- Observ. Microscop. sur les animalcules de Carlsbad, p. 18.
5. D. bifidum (Ehr.). See Staurastrum bifidum.
2. A. Baileyi --- ; filament not crenated; joints about equal in length and breadth.
Odontella? tridentata, Bailey, in lit. cum icone (1846).
Worden's Pond, Rhode Island; near Princeton, New Jersey, with sporangia, Bailey.
Filament triangular; joints excavated at their junction like those of Aptogonum Desmidium. The joints are not bicrenate, hence the margins of the filament are entire, a character which distinguishes it from that species. The end view is triangular, with rounded angles.
Professor Bailey has sent me a drawing of the conjugated state, very interesting from its resemblance to a condition of Desmidium Swartzii, which I had doubtfully regarded as the sporangia of that species. In both plants it is difficult to understand the process or to distinguish the coupled filaments, since the appearance is merely that of a much-enlarged and torn filament.
Tab. XXXV. fig. 1. from drawings by Professor Bailey; a. portion of a filament; b. transverse view; c. sporangia highly magnified.
3. S. lamelliferum (Corda).
Carlsbad, Corda.
"Chaînes courtes, les membres doubles presque uniformes; un tiers est découpé transversalement des deux côtés; lobes rapprochés l'un de l'autre, arrondis; cuirasse unie, transparente et blanche. Le membre de réunion feuilleté, blanc."--- Corda, l. c.
4. S. pulchrum (Bailey); joints twice as broad as long, deeply incised on each side; junction-margins straight, connected by short bands.
West Point, New York; and Princeton, New Jersey, Bailey.
Professor Bailey informs me that this species is twice as large as Sphaerozosma vertebratum. His figure represents the filament diminishing and increasing in breadth at intervals, an appearance probably caused by the twisting of the plant. Sphaerozosma pulchrum agrees with S. vertebratum in the presence of a mucous tube, and also in the form of the joints; but not in the mode of their connexion with each other. It differs from Corda's figure of S. lamelliferum, inasmuch as its segments are not reniform.
Tab. XXXV. fig. 2. a. portion of a filament; b. joints with mucous tube, from drawings by Professor Bailey.
5. S.? filiforme (Ehr.); joints bilobed, united by double slender processes which inclose a quadrate foramen between each pair.
Germany, Ehrenberg, Kützing.
14. M. apiculata (Ehr.); frond orbicular rough with scattered spines; segments five-lobed, lobes incised and toothed, end lobe narrow.
Germany, Ehrenberg. Falaise, Brébisson.
Specimens sent me by M. de Brébisson have deeper incisions than that figured by Ehrenberg, and are also smaller.
15. M. quadragies-cuspidata (Corda); frond with scattered hair-like spines; end lobe the broadest.
Euastrum aculeatum, Ehrenberg, Infus. t. 12. f. 2 (1838).
Micrasterias apiculata, Meneghini, Synop. Desmid. in Linnaea 1840, p. 216. Brébisson, in lit. cum specimine.
Cosmarium quadragies-cuspidatum, Corda, Observ. Microscop. sur les Animalc. de Carlsbad, p. 30. t. 6. f. 40 (1840).
Carlsbad, Corda.
This plant bears the same relation to Micrasterias apiculata which M. crenata and M. truncata bear to M. denticulata and M. rotata. I subjoin the following description from Corda's work : ---
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"Corpuscules chevelus, verts, presque à six lobes. Lobe du milieu triangulaire, les coins extérieurs à deux pointes; au milieu, deux cylindres vert foncé, appuyés l'un contre l'autre. Chaque lobe latéral a trois découpures, et chaque découpure a deux dents."
16. M. foliacea (Bailey); frond subquadrate; end lobes narrow, with emarginate angles; lateral lobes inciso-dentate, with a short rounded tooth-like projection next the end lobe.
Micrasterias foliacea, Bailey, in lit. cum icone (1847).
Worden's Pond, Rhode Island, Bailey.
"Frond small, smooth, nearly quadrangular in the general outline: segments composed of three principal lobes, of which the middle one is nearly simple and emarginate: the lateral lobes are incised, in much the same manner as in Micrasterias rotata, and all their subdivisions extend to an equal distance from the middle line of the frond." --- Bailey, in lit.
Tab. XXXV. fig. 3. Frond dividing, from a drawing by Professor Bailey.
17. M. Torreyi (Bailey); frond orbicular; lateral lobes deeply incised; inner subdivisions acute, external bidentate at the apex, all tapering.
Near Princeton, New Jersey, Bailey.
This species connects the elliptic with the orbicular species. The end lobe is narrow and not exserted; the angles taper into acute points or spines. All the incisions are deep. The lateral lobes have five subdivisions, two belonging to the basal lobe and three to the intermediate; but the distinction is obscure, and only indicated by the rather deeper incision which parts them. Of the subdivisions, that next the other segment and that adjacent to the end lobe are bidentate at the apex, the rest taper gradually into acute points.
Tab. XXXV. fig. 5. Frond from a drawing by Professor Bailey.
18. M. muricata (Bailey); "segments divided by deep indentations into three transverse portions; the basal with three linear processes on each side, the others with two on each side."
Catskill Mountains, United States, Bailey.
Micrasterias muricata belongs to the same section as M. furcata, but differs from that and every other known species in some remarkable particulars. The division into five lobes is indicated merely by the presence of processes, which, unlike those in the other species, do not diverge in the front view, but spread laterally, in such a manner that the one nearest the eye more or less conceals its companions.
19. M. Baileyi --- ; frond granulated; segments three-lobed; lobes bipartite, end one much-exserted.
West Point, New York; and Rhode Island, Bailey.
Micrasterias Baileyi is allied to M. furcata and M. Crux-Melitensis; the frond however is minutely granulate, the segments are only three-lobed, and the end lobe is more exserted than it is in those species. The basal lobes are deeply bipartite, the end one merely sinuated. All the subdivisions are bidentate at the apex.
Tab. XXXV. fig. 4. Empty frond: from a drawing by Professor Bailey.
20. M. incisa (Kütz.); lobes horizontal, basal ones truncate, with a tooth at each angle; end lobe convex, its angles acute.
Germany, Ehrenberg. Falaise, Brébisson.
Euastrum incisum, Brébisson, Meneghini, Synop. Desmid. in Linnaea 1840, p. 216. Kützing, Phyc. Germ. p. 134.
Micrasterias incisa, Brébisson, in lit. (1846).
19. E. cornutum (Kütz.); segments three-lobed; terminal lobe cuneate, included between two process-like projections of the basal portion.
Euastrum cornutum, Kützing, Phycologia Germanica, p. 135 (1845); in lit. cum icone.
Germany, Kützing.
The frond resembles that of Euastrum crassum, but the outer angles of the basal portion of each segment are prolonged into rostrate-like processes which include the terminal lobe between them.
Tab. XXXV. fig. 13. Frond: from a drawing by Professor Kützing.
20. E. Pelta (Corda); segments quadrangular; end margin with a rounded protuberance at each corner; lateral margins with a small protuberance at the basal end and a larger one near the outer end.
21. E. crenatum (Kützing).
Euastrum crenatum, Kützing, Phycologia Germanica, p. 135 (1845).
Dalmatia, Kützing.
This plant may be a variety of Euastrum elegans.
Tab. XXXV. fig. 14. Frond: from a drawing by Professor Kützing.
22. E. crenulatum (Ehr.).
Germany, Ehrenberg.
I am unacquainted with the characters of this species.
34. C. Palangula (Bréb.).
Falaise, Brébisson.
M. de Brébisson informs me that " Le Cosmarium Palangula me semble se distinguer du Cos. Cucurbita par sa forme plus cylindrique, tronquée et non en Courge, ses séries de points plus fines, transverses et non longitudinales." I am however unable to distinguish this species from C. Cucurbita, for the puncta are scattered in British specimens of the latter.
35. C. lagenarium (Corda); segments triangular, all the angles broadly rounded.
36. C. Papilio (Menegh.); segments smooth, triangular, with rectangular apex; end view linear, with a lobe at the middle of each side.
37. C. ventricosum (Kütz.).
C. ventricosum, Kützing, Phycologia Germanica, p. 136 (1845); in lit. cum icone.
I believe this to be a species of Cosmarium in a dividing state.
7. X. Artiscon (Ehr.); segments narrowed at the base; end margin with numerous elongated spines which are divided at the apex.
Xanthidium, No. 2, Bailey, American Journal of Science and Arts, v. 41. p. 291. t. 1. f. 15 (1841).
Xanthidium Artiscon, Ehrenberg, Verbreitung und Einfluss des Mikroskopischen Lebens in Süd- und Nord-Amerika (1843).
West Point, New York, Bailey.
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Xanthidium Artiscon differs from X. armatum by its segments tapering at the base: its spines also are much longer and are more restricted to the outer and rounded margin.
Several plants referred by Ehrenberg to Xanthidium are angular in the end view, and properly belong to Staurastrum.
8. X. furcatum (Ehr.); "corpuscules globose, green, single or binate, spinous; spines scattered, forked at the apex."
Xanthidium furcatum, Ehrenberg, Infus. p. 148. t. 10. f. 25 (1838); Meteorp. t. 1. f. 21.
This plant is probably a Staurastrum. M. de Brébisson refers it to S. spinosum, and Professor Kützing makes it a synonym of his Phycastrum furcigerum (Didymocladon furcigerus). Of neither have I seen specimens resembling Ehrenberg's figure, from which indeed I believe the latter plant is very distinct.
3. A. minutus (Kütz.).
Germany, Kützing.
Tab. XXXV. fig. 15. a, b. perfect fronds; c. dividing frond: from drawings by Professor Kützing.
4. A. ? truncatus (Ehr.); "corpuscules green, slightly compressed, campanulate, geminate, externally truncate, spinous."
Arthrodesmus truncatus, Ehrenberg, Infus. p. 152 (1838).
This plant is probably either a Xanthidium or a Staurastrum.
39. S. pygmaeum (Bréb.); segments cuneiform; end view triangular, with slightly rounded sides.
Falaise, Brébisson.
Staurastrum pygmaeum is smaller than S. alternans, its sides, in the end view, are more convex, and its angles less rounded. The sporangium is orbicular and spinous. Mr. Jenner informs me that he has seen this species amongst other Desmidieae which I had forwarded from Dolgelley; and Mr. Thwaites has given me its sporangia, gathered near Devonport by Mr. Dansey.
Tab. XXXV. fig. 26. from drawings by M. de Brébisson: a. front view of frond; b. immature sporangium; c. mature sporangium.
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40. S. rugulosum (Bréb.); segments elliptic, denticulate at their sides; end view triangular, with the angles broadly rounded and denticulate.
Euastrum, No. 9, Bailey, American Journ. of Science and Arts, v. 41. p. 296. t. 1. f. 9 (1841).
Staurastrum rugulosum, Brébisson, in lit. cum icone (1846).
West Point, New York, Bailey. Falaise, Brébisson.
Tab. XXXV. fig. 19. from drawings by M. de Brébisson: a. front view; b. end view.
41. S. scabrum (Bréb.); segments elliptic, scabrous; end view triangular, fringed with minute emarginate spines.
Staurastrum scabrum, Brébisson, in lit. cum icone (1846).
Falaise, Brébisson.
Tab. XXXV. fig. 20. from drawings by M. de Brébisson: a. front view; b. end view.
42. S. bacillare (Bréb.); frond smooth; processes capitate; end view with three to five capitate rays or processes.
Falaise, Brébisson.
Frond smooth; processes in front view stout, divergent, each terminated by a round knob; end view three- to five-rayed, the rays capitate in the same manner as in the front view.
A remarkable and very distinct species.
Tab. XXXV. fig. 21. from drawings by M. de Brébisson: a. front view of frond; b, c, d. transverse views.
43. S. Capitulum (Bréb.); segments quadrate, sinuated on each side, prominences rough; end view triangular, with broadly rounded angles.
Staurastrum bacillare, Bréb., Meneghini, Synop. Desmid. in Linnaea 1840, p. 228. Brébisson, in lit. cum icone.
Falaise, Brébisson.
Frond quadrilateral, nearly twice as long as broad; constriction shallow; the segments have two rounded prominences on each side and a small semi-circular sinus between them; these prominences are rough with minute granules, which give them a crenate appearance. End margin straight. End view triangular, the angles broadly rounded; sides nearly straight, but each
slightly constricted at the middle.
Tab. XXXV. fig. 25. from drawings by M. de Brébisson: a. front view of frond; b. end view.
44. S. pileolatum (Bréb.); frond quadrilateral, slightly constricted at the middle; segments terminated by three conical processes.
Staurastrum pileolatum, Brébisson, in lit. cum icone (1846).
Falaise, Brébisson.
Frond twice as long as broad; segments quadrate, with a broad, shallow sinus on each side; the end terminated by three conspicuous conical processes, which are rough with minute granules. End view triangular, the angles rounded.
Tab. XXXV. fig. 22. from drawings by M. de Brébisson: a. front view of frond; b. end view.
45. S. echinatum (Bréb.).
Falaise, Brébisson.
This species appears, from M. de Brébisson's drawings, to be closely allied to Staurastrum hirsutum and S. teliferum.
Tab. XXXV. fig. 24. from drawings by M. de Brébisson: a. front view of frond; b. end view.
46. S. crenatum --- ; segments cuneate; outer margins crenate; end view with three truncate and crenate angles.
Rhode Island, Bailey.
Tab.XXXV fig. 17. a. front view of frond; b. end view: from drawings by Professor Bailey.
47. S. bifidum (Ehr.); frond smooth; end view with three cloven angles.
Desmidium bifidum, Ehr. Abh. der Berlin. Ak. 1832, p. 292; Infusor. p. 141. t. 10. f. 11.
Phycastrum bifidum, Kützing, Phycologia Germanica, p. 138 (1845).
Staurastrum bifidum, Brébisson, in lit. (1846).
48. S. eustephanum (Ehr.); end view triangular with six emarginate spines on the upper surface; each angle terminated by a short ray tipped with spines.
West Point, New York, Bailey.
49. S. senarium, Ehr.
West Point, New York, Bailey.
Ehrenberg's figure represents the end view as triangular, the angles terminating in short rays, which are tipped by minute spines: on each side are two short forked spines, and six others on the upper surface. His figure agrees in some respects with Staurastrum spinosum, consequently S. senarium may prove a variety of that very variable species.
50. S. Ehrenbergii, Corda.
Xanthidium Ehrenbergii, Corda, 0bserv. Microscopiques sur les Animalcules de Carlsbad, p. 29. t. 5. f. 36, 37 (1840).
Prague, Corda.
"Corpuscules par paire, vus de côté, ovales; vus d'en haut, triangulaires, munis de six appendices terminaux et lateraux, et de deux autres appendices centraux, qui sont courts, blancs, en fourchette, mais à pointes divergentes" --- Corda, l. c.
Corda's figure of the front view resembles Staurastrum spinosum.
51. S. articulatum, Corda.
Xanthidium articulatum, Corda, Observ. Microscopiques sur les Animalcules de Carlsbad, p. 28. t. 5. f. 35 (1840).
Carlsbad, Prague and Reichenberg, Corda.
"Corpuscules ovales, par paire, munis aux deux bouts d' un appendice à deux cellules, qui se divise encore en forme de fourchette; et lateralement en deux appendices plus longs à quatre cellules, et une pointe en fourchette. Sur les deux côtés plats, se trouvent deux protubérances transversales, également pourvues de deux allongements cellulaires en fourchette." --- Corda, l. c.
52. S. coronatum (Ehr.); end view triangular and terminating at each angle in three short, diverging arms which are divided at the apex.
West Point, New York, Bailey.
Professor Bailey's figure, which in a list of American Desmidieae obligingly communicated he refers to as Xanthidium coronatum, Ehr., in the front view resembles Xanthidium Artiscon, whilst Ehrenberg's appears to me a good representation of the front view of Didymocladon furcigerus. I doubt therefore whether these two figures can represent the same species.
53. S.? minus (Kütz.); frond smooth; end view with five slender acute rays.
Pentasterias minor, Kützing, Phycologia Generalis, p. 162 (1843).
Nordhausen, Prussia, Kützing.
Tab. XXXV. fig. 18. a, b. Fronds: from drawings by Professor Kützing.
Xanthidium coronatum, Ehrenberg, Verbr. und Einfluss des Mikrosk. Lebens in Süd- und Nord-Amerika, t. 4. f. 26 (1843).
Phycastrum? minus, Kützing, Phycologia Germanica, p. 139 (1845); in lit. cum icone.
54. S. glabrum (Ehr.); frond smooth; end view triangular, each angle terminated by a mucro-like spine.
West Point, New York, Bailey. Germany, Ehrenberg.
This species is probably identical with Staurastrum Avicula.
Desmidium glabrum, Ehrenberg, Verbreitung und Einfluss des Mikrosk. Lebens in Süd- und Nord-Amerika (1843); Meteorp. t. 1. f. 3.
Phycastrum glabrum, Kützing, Phycologia Germanica, p. 137 (1845).
55. S. granulosum (Ehr.).
Desmidium granulosum, Ehrenberg, Meteorp. t. 1. f. 12.
Phycastrum granulosum, Kützing, Phycologia Germanica, p. 138 (1845).
Germany, Ehrenberg.
This species is known to me only by name.
56. S. globulatum (Bréb.); segments fusiform, capitate; end view (angu?)lar, each angle terminated by a granulated knob.
Falaise, Brébisson.
Tab. XXXV. fig. 23. a. end view of frond; b. front view: from drawings by M. de Brébisson.
8. D. coronatum (Bréb.); frond stout; suture projecting on each side; segments inflated at the base and bordered by tubercles at the end.
Docidium coronatum, Brébisson, in lit. cum icone (1846).
Falaise, Brébisson.
This species agrees with Docidium nodulosum not only in size and form, but in having a suture projecting on each side, and also in its segments, which have undulated margins; but it is distinguished from that plant by having the ends bordered with minute but distinct tubercles. The end view is circular, the margin crenate. Docidium coronatum differs from D. Ehrenbergii in its larger size and projecting suture.
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Tab. XXXV. fig. 6. a. empty segment; b. end view: from drawings by M. de Brébisson.
9. D. nodosum (Bailey); frond stout; segments with four prominent nodes separated by constrictions; end view crenate.
United States, Bailey.
An end view shows that each node is not a simple swelling, but really formed by whorls of tubercles.
" This species is easily recognised by the deep indentations in its outline, corresponding to the constrictions which separate the transverse rows of knot-like projections. It is one of the largest species in the genus." --- Bailey, l. c.
Tab. XXXV. fig. 8. a. empty segment; b. end view: from drawings by Professor Bailey.
10. D. constrictum (Bailey); frond stout; segments with moderately deep constrictions, which separate four equal, gently curving prominences; end view entire.
Worden's Pond, Rhode Island, Bailey.
"This species is at once distinguished from Docidium nodosum by the cross section of the nodes being a simple circle instead of an indented one." --- Bailey, in lit.
ab. XXXV. fig. 7. from drawings by Professor Bailey: a. front view; b. end view.
11. D. verrucosum (Bailey); Segments with numerous whorls of small prominences which give the margins an undulated appearance, all the undulations equal.
Closterium verrucosum, Bailey, American Journal of Science and Arts, 1846, v. 1. p. 127. f. 4.
New York; Rhode Island, Bailey.
"This is a very pretty species with a waved outline, caused by the slight projections, which are arranged in numerous transverse rings." --- Bailey, l. c.
12. D. verticillatum (Bailey); segments with numerous whorls of tooth-like projections; ends with three bidentate processes.
Worden's Pond, Rhode Island; Princeton, New Jersey, Bailey.
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A most remarkable and interesting plant, for a specimen of which I am indebted to Professor Bailey.
The triple terminal processes are so unlike what we find in other species of Docidium, that Professor Bailey, in a letter to me, proposes to form a new genus for the reception of this plant.
Tab. XXXV. fig. 9. a. empty frond; b, c. empty segments; d, e. extremities highly magnified: from drawings by Professor Bailey.
Triploceras verticillatum, Bailey, in lit. (1847).
13. D. crenulatum (Ehr.).
Professor Bailey informs me that this plant is identical with Docidium nodulosum.
23. C. cuspidatum (Bailey); frond smooth, crescent-shaped; ends mucronate.
Worden's Pond, Rhode Island, Bailey.
Closterium cuspidatum differs from every other species of the genus in having each end tipped by a spine or mucro.
Tab. XXXV. fig. 11. Frond: from a drawing by Professor Bailey.
24. C. Cucumis (Ehr.); frond smooth, stout, semilunate; ends broadly rounded.
Closterium Cucumis, Ehrenberg, Verbreitung und Einfluss des Mikosk. Lebens in Süd- und Nord-Amerika, t. 4. f. 29 (1843).
New York, Bailey.
Ehrenberg's figure represents this species about five times longer than broad, in form resembling Closterium Lunula, but stouter in proportion to its length, and having more rounded ends.
25. C. Thureti (Bréb.); frond smooth, crescent-shaped; ends subacute; margins unconnected at the suture; vesicles in a single series.
Falaise, Brébisson.
26. C. arcuatum (Bréb.); frond smooth, slender-crescent-shaped; ends obtuse, scarcely notched.
Falaise, Brébisson. Germany, Kützing.
I am unable to distinguish Closterium arcuatum from C. Dianae; but in drawings sent me by M. de Brébisson, the latter has distinct terminal notches, which are wanting in the former.
27. C. Venus (Kütz.).
Closterium venus, Kützing, Phycologia Germanica, p. 130 (1845); in lit. cum icone.
Germany, Kützing.
I am indebted to Professor Kützing's kindness for a drawing of this species, but I must confess that I am unable to discover any characters sufficient to distinguish it from Closterium Dianae.
Tab. XXXV. fig. 12. Frond, from a drawing by Professor Kützing.
28. C. Amblyonema (Ehr.); frond stout, linear slightly curved, twenty times longer than broad; ends rounded.
Closterium lineatum, Bailey, American Journ. of Science and Arts, v. 41. p. 303. t. 1. f. 34 (1841).?
Closterium Amblyonema, Ehrenberg, Verbreitung und Einfluss des Mikrosk. Lebens in Süd- und Nord-Amerika (1843).
29. C. uncinatum (Kütz.); frond slender, finely and closely striated; extremities tapering to a subacute point and suddenly curved downwards.
Germany, Kützing.
30. C. decussatum (Kütz.); frond stout, finely and closely striated, slightly curved, gradually tapering; extremities slender, but obtuse at the apex.
Closterium decussatum, Kützing, Phycologia Germanica, p. 131 (1845); in lit. cum icone.
Germany, Kützing.
A drawing sent me by Professor Kützing represents the striae as regularly crossing each other, so as to form diamond-shaped reticulations. As this appearance is not unusual in dried specimens, when the flattened frond permits the striae of both surfaces to be visible together, I will venture to suggest the possibility that Professor Kützing's drawing may have been taken from a frond in that condition. Closterium decussatum seems to differ from C. turgidum in its more tapering extremities.
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31. C. turgidulum (Kütz.); frond stout, curved; extremities slender, gradually tapering; striae few, conspicuous.
Germany, Kützing.
Closterium turgidulum differs from C. costatum in its more elongated extremities.
32. C. obtusangulum (Corda).
Carlsbad, Corda.
"Corps courbé en croissant, quadrangulaire; coins ronds. Cuirasse unie, blanche, arrondie vers les pointes, et transparente; au milieu un ruban transversal étroit, blanc et transparent. Pas de vésicules rotatoires dans les pointes, mais beaucoup de corpuscules rotatoires, ovales, transparents, blancs, se mouvant vivement."--- Corda, l. c.
33. C. inaequale (Ehr.); minute, semilunate; extremities unequal, conic, ends acute; striae prominent; vesicles scattered.
Germany, Ehrenberg, Kützing.
34. C . quadrangulare (Corda).
Carlsbad; Reichenberg, Corda.
"Long, corps mince, quadrangulaire. Coins aigus. Cuirasse unie, transparente, blanche. Substance interne vert foncé, à petits grains. Sur les pointes les quatre surfaces de la cuirasse sont obliquement coupées, et la pointe arrondie. Elle contient de grosses vésicules rotatoires, bien limitées, d'un rouge pâle, avec plusieurs corpuscules rotatoires elliptiques et rougeâtres." --- Corda, l. c.
35. C. gracile (Bréb.); frond slender, smooth, lanceolate, gradually tapering into short beaks, which are curved downwards.
Closterium gracile, Brébisson, Meneghini, Synop. Desmid. in Linnaea 1840, p. 234, under C. lineatum.
Stauroceras gracile, Brébisson, in lit. cum icone (1846).
Falaise, Brébisson.
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Closterium gracile differs from the other rostrate species in its smooth frond. Its beaks are shorter than those of C. rostratum and C. setaceum, and its frond is less inflated.
36. C. tenerrimum (Kütz.).
Nordhausen, Kützing.
I can perceive in Professor Kützing's drawing no character by which this plant can be separated from Closterium acutum.
Tab. XXXV. fig. 10. Fronds: from a drawing by Professor Kützing.
2. A. fusiformis (Corda).
Carlsbad, Corda.
3. A. convolutus (Corda).
Ankistrodesmus convolutus, Corda, Almanach de Carlsbad 1838, p. 199. t. 2. f. 19.
Carlsbad, Corda
I am unacquainted with the characters of these species.
7. S. antennatus (Bréb.); cells fusiform, somewhat ventricose at the middle; ends cuspidate, each terminated by a minute orbicular globule.
Falaise, Brébisson.
Scenedesmus antennatus resembles S. obliquus in form, and also in the arrangement of its cells; but it is distinguished from that and every other species by having the attenuated points tipped by minute globules.
Tab. XXXV. fig. 27. a, b. different states of frond: from drawings by M. de Brébisson.
