320 MESSRS. W. WEST AND G. S. WEST ON 
spines parallel" (H. J. no. 309). De Land, Florida; * very 
strong spines, strongly recurved.” Seattle, Wash.; “a rather 
slender form.” 
164. ArTHRODESMUS CURVATUS, W. B. Turn. in K. Sv. Vet.- 
Akad, Handl. xxv. no. 5, p. 135, t. 11. ff. 31, 33, t. 12. ff 2, 7, 
11, 13, et 15. 
Forma cellulis late ellipticis ; long. 64; lat. s. spin. 46 p; 
long. spin. 20 u; lat. isthm. 9 u. 
Hab. De Land, Florida (H. J. no. 559). 
165. A. Incus, Hass. 1845; Ralfs, Brit. Desm. p. 118, t. 20. 
f. 4 a-d. 
Var. vaLipus, n. var. (Pl. 17. fig. 16.) 
Var. semicellulis obverse semicireularibus, apicibus subrectis, 
spinis longis validis divergentibus. 
Long. s. spin. 35 p, c. spin. 111 p; lat. s. spin. 36 p, c. spin. 76 p ; 
long. spin. 42 u; crass. spin. ad bas. 3'5 u; lat. isthm. 86 p. 
Hab. De Land, Florida. 
These are the largest specimens of this species we have yet 
observed; in form they agree with one of the figures given by 
Wolle (Desm. U. S. pl. 24. fig. 3). 
166. A. TRIANGULARIS, Lagerh. in Ofvers. K. Vet.-Akad Fork. 
1885, no. 7, p. 244, t. 27. f. 22. 
Var. INFLATUS, n. var. . 
Var. semicellulis latissime angulari-ellipticis, apicibus elevatis 
truncatisque, spinis validioribus et levissime extrorsum curvatis. 
Long. 38 p; lat. s. spin. 21 u, c. spin. 72 p; lat. isthm. 7 p. 
Hab. Laconia, N.H. (H. J. no. 659). 
XIX. SPHZEROZOSMA, Corda. 
167. S. Warum, Jacobs. in Botan. Tidsskr. viii. (1874), 
p. 211.—S. excavatum, var. B, Wallich. 
Hab. Burlington, Kans. Seattle, Wash. 
XX. DESMIDIUM, 4g. 
168. D. aproconum, Bréb. 1835.—Aptogonum Des 
Ralfs, Brit. Desm. p. 64, t. 32. f. 1. . J 
Hab. Duval Co., Florida, abundant and conjugating (H. e 
no. 295). 
midium, 
