4 three-toothed apex; the inferior horns curved inwards, seen from 
the vertex quadrangular, hollowed at the sides. Membrane smooth. 
Length of cell without horns, 58-59 v3 with horns, 117 »; breadth 
of ze A sady horns, 104 #; breadth of isthmus, 15-16 p.—Borge. 
8. bicorne, var. longebrachiatum, Borge (n. var.)._ Varia- 
hi with sides of semi-cells furnished on each side with three denticu- 
- Processes ; apex furnished with one series of processes, seen from 
€ vertex semi-cells furnished with two rows of processes ; rays longer, 
aa with bidentate apex. Membrane smooth. Length of 
»e0-94 “; breadth with rays, 74-85 «; breadth of isthmus 9 p. 
(Plate XIV.) es gis 
Hab.: Waters of the Gulf country, Dr. Thos. L. Bancroft. 
: tha tere after some reflection assigned this form to S. bicorne; it differs from 
1... Pecies by the sensibly longer and slender processes, by the protuberances inthe 
ails, however, in many respects S. bicorne, var. Australis, Rac. Desmidya 
“oncaeAg 22, Plate IT., fig. 8. Compare also S. bengalense, Turner, Alger o 
. ndia, p. 124, Plate XIV., fig. 13. (Plate XVIT.)—Borge. 
an ome extent inflated, truncated at the apex, corners proceeding into 
; fides hotee t arms granulated; in vertical view semi-cells 3 cornered ; 
breadth owed. Length of cell with arms, 52 »; greatest breadth, 26 p; 
Te of isthmus, 9-10 y.—Borge. (Plate XVIT.) 
bh Waters of the Gulf country, Dr. Thos. L. Bancroft. 
Mestessi'4°° S. zonatum, Bérg., Desm. Bras., p. 951, Plate V., fig. 48, and S.. 
. > “urner, Aleve of East india, p. 131, Plate XVL,, fig 21. 
frbteulare, Ralfs. Segment smooth, semi-orbicular ; end view 
Size. 6 langular, Zygospore orbicular, beset with subulate spines. 
2.50 H; diameter, 25 pw (D.); diameter, 30-45 » CBP aD aarti 
-Desmids (K.); length, 32 ~; diameter, 27 » (N.).—Cooke’s Britis 
p76. (Plate VIIL) : 
F tds, Py ulare, 6 depressum, Royet Bisset. Japanese Des- 
-z, Bte 269, fiz. 14, and Racib. (ubi. sup.), Plate IL, fig. 17 
ot Jenkins’ Quarry, Bundamba, and Blackstone, Ipswich, W. J. Byram. 
- pi iculare, 8 denticulatum, Nordst. ae 
é 2 Gating, POCkingham Bay, J. Dallachy; between Norman and Gilbert Rivers, 
blunt angles, 
tly convex, zygo bicular, beset with protuberances, 
’ spore orbicular, beset with pr 
8 each two bitte spines at their summits. Size: Lengt h, 
*s British 
187. (Plate X 
iform, outer 
