1888-89.] Mr John Rattray on the Genus Coseinodiscus. 509 
The valve named C. decipiens , Gran. (Sch., Atl., pi. lix. fig. 18), 
from Table Bay, is distinct, though Grunow has proposed to unite 
them ; in the latter the markings are largest at the centre, and the 
apiculi are more prominent. 
Habitat. — Antarctic, Kerguelen (Grunow). 
C. lanceolatus. Cstr., Diat. Chall. Exped ., p. 164, pi. xvih 
fig. 19. — Elliptical to subdiamond-shaped. Major axis *0775 mm., 
about 2J times minor. Central space and rosette absent. Markings 
polygonal, largest and subequal on a small indefinite central area, 
thence decreasing to the border; at the centre 3, at the border 6 in 
*01 mm.; irregular or in faint radial rows. 
This species forms a transition to the untenable genus Stoschia. 
Habitat. — South of Australia, H.M.S. Challenger (Castracane). 
C. velatus. Ehrb., Mon. Ber. Ah ., 1844, p. 78. — Diam. about 
•055 mm. Central space and rosette absent. Markings angular, 
robust, pearly, about 2J in *01 mm., punctate; rows obscurely 
radial, subregularly concentric. — Ehrb., Mihrog ., pi. xviii. fig. 37 ; 
Ralfs in Pritch. Inf., p. 830. 
Ehrenberg regarded this species as probably belonging to Eupo- 
discus. With this, owing to the absence of processes, it cannot be 
united. It is closely allied to Steplianopyxis. It also approaches 
C. marginatus. 
Habitat. — Richmond deposit, Va. (Ehrenberg). 
O. marginatus. Ehrb., Abli. Ber. Ah., 1841, p. 142. — Diam. from 
*0375 to T5 mm. Central space absent. Markings polygonal, 
somewhat pearly, with large, round central papillae ; towards the 
centre 2 to 2J in *01 mm., decreasing gradually towards the border. 
Border distinct, *0025 to *0075 mm. broad, with coarse striae, 4 in 
*01 mm. — Ehrb., Mihrog., pi. xviii. fig. 44; pi. xxxiii. 12. fig. 13; 
pi. xxxviii. B. 22. fig. 8; Cleve and Moll., Diat., Ho. 114, 164, 215 ; 
H. L. Sm., Diat. Sp. Typ., Nos. 94, 95; Sch., Atl., pi. lxii. figs. 1, 2, 
3, 4, 5, 9, 11, 12 ; pi. lix. fig. 11 (no name) ; C. fimbriatus limbatus ,* 
Ehrb., Mihrog., pi. xix. fig. 4 ; Sch., Atl., pi. lxv. figs. 3-6 ; pi. 
cxiii. fig. 2; C. limbatus, Ehrb., Mon. Ber. Ah., 1840, p. 206; 
* Quoted “ C. fimbriato-limbatus by Grunow, Denk. Wien. Ah., 1884, p. 
72 . 
