284 MESSRS. W. WEST AND G. S. WEST ON 
24. CrosrERIUM Rarrsir, Bréb. in Jenner, Fl. Tunbr. Wells, 
p. x; Ralfs, Brit. Desm. p. 174, t. 30. f. 2. 
Var. HyBRIDUM, Rabenh. Fl. Europ. Alg. iii. p. 185. 
Long. 408 y ; lat. 32 u. 
Hab. Bridgeport, Conn. 
25. C. srRri0LATUM, .Ehrenb.; Ralfs, Brit. Desm. p. 170, 
t. 2 g et f. 
Hab. Portland, Oregon: “a short form very like C. didymo- i 
tocum in shape and size, but coarsely striate. Very abundant ” 
(H. J. no. 415). Meredith, N.H., and Plymouth, N.H.: “forms 
like C. didymotocum except that ends were more rounded ; coarsely 
striate ; several cross-lines ; upper margin nearly straight ; diam. 
40,4" (H. J. no. 382). This may be var. orthonotum, Roy. 
Near Tallahassee, Florida: “a long form nearly straight on 
ventral margin and with truncate ends"; diam. 50, (H. J. 
no. 478). 
26. C. prrEctuM, Arch. in Proc. Dubl. Nat. Hist. Soc. (1862) 
p. 80, t. 2. ff. 23, 24. 
Long. 170 p; lat. 11 p. 
Hab. New Connecticut (H. J. no. 536). 
27. C. Jounsoni, n. sp. (Pl. 16. figs. 1, 2.) 
Cl. mediocre, cellulis diametro circiter 17-plo longioribus, sub- 
rectis et leviter sigmoideis, lateribus parallelis sed apices versus 
gradatim attenuatis, apicibus subtruncatis ; membrana glabra. 
Long. 357 p; lat. 21 p; lat. apic. 12 p. 
Hab. Plymouth, N.H. (H. J. no. 655). 
This species seems to be sufficiently characteristic. 
28. C. Toxon, West, in Journ. Linn. Soc. (Bot.) xxix. p. 121, 
pl. 19. f. 14. 
Forma Etoneata. (Pl. 16. figs. 3, 4.) 
Long. 350 u; lat. 6-9 y. 
Hab. Florida (H. J. nos. 485 & 564). 
29. C. TUMIDUM, Johns. in Bull. Torr. Bot. Club, xxii. (1895) 
p. 291, pl. 239. f. 4.—C. Cornu f, Ralfs. 
Long. 130 p; lat. 14-18 p. 
Hab. Horse Plains, Mont., frequent (H. J. no. 626). Holder- 
ness, N.H., frequent. 
30. C. Dranx, Ehrenb.; Ralfe, Brit. Desm. p. 168, t 28. f. 
Lat. 20-25 p. 
