268 MR. W. WEST ON SOME FRESHWATER 
Norges Desm. p. 28, t. 1. f. 8). Forma minor, Nordst. (J. c.). 
(Pl). XIII. fig. 17.) 
Long. 14°5 p; lat. 11°53 lat. isthm. 6°5 x; crass. 9°5 pw. 
Hab. Amongst Symploca cuspidata, n. sp., on trees, summit of 
Trois Pitons (4500 ft.), Dominica. No. 904. 
This interesting species seems to have a varied kind of habitat, 
occurring in small upland tarns and pools, on dripping subalpine 
rocks, and in the present instance on damp mossy trees. 
11. Cosmartum Cucursira, Bréb. (Ralfs, Brit. Desm. p. 108, 
t. 17.4.7.) 
Long. 40 p; lat. 21 pw; lat. isthm. 19 p. 
Hab. On trees among mosses, summit of Trois Pitons (4500 ft.), 
Dominica. No. 903. 
Class C@NOBIES. 
Ord. VoLVocINEz. 
12. Euportna staGNnaLe, Wolle. (Freshw. Alg. of U.S. p. 160, 
pl. clii. figs. 11-21.) 
Var. cellulis parvis et distantibus. (PI. XVI. fig. 10.) 
Diam. cel]. 4°8-5°6 x; diam. ccenob. 63 pe 
Hab. Amongst mosses on trees, with Hapalosiphon intricatus, 
n. sp., and Symploca cuspidata, n. sp.. summit of Trois Pitous 
(4500 ft.), Dominica. No. 903. 
Class PROTOCOCCOIDES. 
Ord. Protococcaces (incl. Palmellacee). 
13. Urococcvs 1nsienis, Kuetz. [Chlorococcus macrococcus, 
Rabh., et var. aureus, Rabh. Fl. Europ. Alg. ii. p. 33.) 
Diam. cell. 23-31 p; ¢. teg. 42 p. 
Hab. On mossy trees, summit of Trois Pitons (4500 ft.), 
Dominica. Nos. 903 and 904, 
14, CERASTERIAS STAURASTROIDES, nov. sp. (PI. XIV. fig. 16.) 
C. quadriradiata e corpore distincto, radiis elongatis sensim 
attenuatis ef minute granulatis, apice obtusis. 
Diam. ¢. proc. 30-35 p; diam. corpor. circ. 9-9°5 p. 
Hab. With Scytonema javanicum, Bornet, amongst mosses, 
on lime-trees, Shantord Estate, Dominica. No. 901. 
The rough arms of this species remind one very forcibly of a 
small Staurastrum, and sufficiently characterize it. 
