298 MESSRS. W. WEST AND G. 8. WEST ON 
profunde fissis, lobulis divergentibus sursum angustatis cum 
apicibus profunde bifurcatis, angulo unoquoque in spinam longam 
producto; semicellulis intra marginem lobi uniuscujusque serie 
spinarum minutarum confertarum instructis. | 
Long. 270 u; lat. 275 p; lat. bas. lob. polar. 26 u ; lat. isthm. 
30 p. 
Hab. De Land, Florida (H. J. no. 580). 
This is a very distinct species and cannot be well confounded 
with any other. 
68. MrcnasTERIAS crenata, Bréb. in Ralfs, Brit. Desm. p. 75, 
t. 7. f. 2, t. 10. f. 4. 
Lat. 76 u. 
Hab. Wake Forest, New Connecticut, occasional (H. J. 
no. 530). 
XIII. XANTHIDIUM, Zhrenb. 
69. X. ANTILOPGUM, Kitz. (1849).—Cosmarium antilopeum, 
Bréb. (1840).—Xanthidium fasciculatum, Ralfs, Brit. Desm. (ex 
parte) t. 20. f. 1a, c. 
Var. MINNEAPOLIENSE, Wolle, 1884. 
A form with the spines nearly half as long as the body and 
very slender; in the centre of the semicells are two or three 
semicircles of granules, and “just below these on each face 
arises a long slender spine which stands out widely. This is not 
at all like other specimens placed here, yet agrees in essential 
features.” 
Long. c. spin. 138 p, s. spin. 72 p; lat. c. spin. 126 p, s. spin. 
641; long. spin. 35 u; lat. isthm. 20; cross. s. spin. 48 p 
Hab. De Land, Florida (H. J. no. 570). 
70. X. conTROVERSUM, n. sp. (Pl. 17. fig. 2.) 
X. antilopeeum ? var., West § G. S. West, in Trans. Linn. Soc., 
Ser. IT. (Bot.), v. p. 252, pl. 16. f. 1. 
X. parvum, 11-plo longius quam latum (sine spinis), profunde 
constrictum, sinu aeutangulo subaperto; semicellule hexagono- 
elliptic, angulis lateralibus et apicalibus spina curvata singt a 
(vel nonnunquam spinis geminatis) preditis, spinis omnibus 
sursum divergentibus; a latere vise globosm; a vertice VIP 
elliptice ; membrana minute punctata, in centro semicellularum 
levissime incrassata. 
Long. c. spin. 55-59 p, 8. spin. 36:5-38 u; lat. c. spin. 52-56 p 
8. spin. 31 u; lat. isthm. 7:6-8 p; crass. 20-21 p- 
