44 W. 15. TURNER, FRESH-WATER ALG.E <)F EAST INDIA. 



ments for and against the removal of the constricted Penia into another genus, but, if re- 

 moved, they would form a section of Cylindrosphincti/um, and immediately follow Docidium. 



Dysphinctium naturally divides into 2 sub-genera, according to the shape of the frond 

 and semicells. 



A. Form cylindrical (nearest to Docidium): 

 Cylindrosptainctiuni (xvXivöqoq, cylindrus; otpn/yco, stringo). 



Typ. sp. Dysph. cylindricum, cucurbita, attenuatum. 



B. Form sub-globose (nearest to Spondylosium and Cosmarium): 

 Sphserosphinctium (ocfaipa, globus; etc.). 



Typ- sp. Dysph. connatuin, Cohnii, globosum (Bulnh.) Nob. 



Gen. 13. Spondylosium, Bréb. 



(Bréb. in KiTZ. Sp. A.lg. p. 189, 1849; Bréb. Liste p. 119, 1850; Leuronema, Wallich Desin. Bengal, 



p. 193, 1860). 



1. Spond. ovale, n. sp. S. mediocre, circ. 1 1 / :s -plo latius quam longum, nudum, cellulis 

 singulis Cosmariiformibus; semicellulae depresso-ellipticae, lateribus rotundatis, isthmo 

 nullo, sinn triangulari-acuto, externe ampliato; membrana glabra. A vertice ovale; a 

 latere modice constrictum, sinu rotundo, sémicellulis globosis. Cörpuscula amylacea bini? 



Long. 20, lat, 28, lat. constr. 9—14, crass. 11 A*. T. XVIII, f. 3. Divisio cellu- 

 larum T. XVIII, f. 9 (sec. Wallich Mscr. No. 65). 



Bengal; also Khasia, ex Utricularia sp., comm. G. v. L. 



2. S. fragile, n. sp. S. minus, paullo latius quam longum, depressum; semicellulae depresso- 

 dolabriformes, apiee truncato-rotundatae, angulis basalibus acutae, sinu latiori, oequali. 

 interne rotundato; isthmuni distinctum ferens; membrana glabra. A vertice visum 

 acuto-ovale; a latere globulatum leviter constrictum. 



Long. 8, lat. 9, lat. isth. 8—3.5, crass. 5.5 ju. T. XVIII, f. 4. 



Nearest to Sphcerozosma (Spön!) pygmoeum Cooke (Br. Desm. p. 5, t. II, f. 5) 

 non Rabii. (as R's sp. is Cosmarium pygmceum Archer, a totally different plant); the 

 shape of the cell and sinus do not, however, agree with Cooke's species. 



3. S. nitens (Wallich) Archer (in Proc. Dubl. Micr. Club, 29 Apl. 1870; Luxdell Desm. 

 Suec. p. 93; Leuronema nitens Wall. Desm. Bengal, p. 193, t, VII, f. 10 — 14, t. \ III, 

 f. 12, 13, 1860). 



S. cellulis paullo latioribus quam longis; zygosporae globosae. Intcrduin con- 

 jugatio lateralis faciens? « typica, Wallich 1. c. f. 10, 11. 



A. No isthmus. 



1. <c typica f. major. Long. 25 — 27, lat. 28 — 30, lat. constr. 9, crass. 16 — 17 w. 

 G. C. W. Mscr. 69. 



2. — — f. minor. Long. 14 — 15, lat, 16 — 17, lat. constr. 7 — 8, crass. ? ju. 



3. var. fi triangulare, n. v. Triangulare, valde constrictum. 



Long. 21 — 25, lat. 24, lat. constr. 8—10 ( «; Wallich 1. c. p. 194, var. f\ 

 t. VIII, f. 12, 13; Mscr. No. 62. 



