278 MR. W. WEST ON SOME FRESHWATER 
51. Evnorta Arcus, Ehrenb. (W. Sm. Brit. Diat. ii. t. 33. 
f, 283.) 
Hab. Instream, crater of Grande Soufriére, Dominica. No. 908. 
52. E. aracizts, Rabh. (Fl. Europ. Alg.i. p. 72.) [Himan- 
tidium gracile, Ehrnb., W. Sm. Brit. Diat. ii. p. 14, t. 33. 
f. 285.] 
Hab. Amongst mosses, on trees, summit of Trois Pitons 
(4500 ft.), Dominica. No. 903. 
58. Oponripium MUTABILE, W. Sm. (Brit. Diat. ii. p. 17, 
t. 34. f. 290.) 
Hab. On damp wall of dam, Sharp’s River, St. Vincent. 
No. 477. 
54. DesMocontuM RaBEeNHorsTIANUM, Grun. (Diat. ins. 
Banka, p. 6, t. 1. f. 1; De Tont, Sylloge Algar. vol. ii. 
p- 680.) 
Hab. Abundant in stream (hot and cold), crater of Grande 
Soufriére, Dominica. No. 908. 
55. Nirzscuta parvuLa, W. Sm. (Brit. Diat.i. p. 41, t. 13. 
f. 106.) 
Hab. On damp wall of dam, Sharp’s River, St. Vincent. 
No. 477. 
56. N. ryexenxa, Suring. (Alg. Japon. p. 11, t. 1. f. 12.) 
Long. 33-44 p ; lat. 3:8-4°8 p. 
Hab. In streams, Grande Soufriére, Dominica. Nos. 881 
and 884. 
57. N. uivearis, W. Sm. (Brit. Diat. i. p. 39, t. 13. 
f. 110.) 
Hab. On damp wall of dam, Sharp’s River, St. Vincent. 
No. 477.—And in streams, Grande Soufriére, Dominica. Nos. 881 
and 908, 
58. N. minurisstma, W. Sm. (L. c. p- 41, t. 18. f. 107.) 
Hab. In stream, Grande Soufri¢re, Dominica. No. 884. 
59. NavicuLa cryprocepHaLa, Kuetz. (W. Sm. I. c. p. 53, 
t. 17, f. 155.) 
Hab. On damp wall of dam, Sharp’s River, St. Vincent. 
No. 477. 
