1888-89.] Mr John Rattray on the Genus Coscinodiscus. 455 
C. turgidus , sp. n. C. velatus , Sch. ? Atl., pi. lxii. fig. 10. — -Diam. 
•0375 to *0625 mm. Surface flat at the centre, convex towards the 
border. Central space absent. Markings polygonal, largest at the 
centre, decreasing rapidly towards the border ; at the centre 3, at the 
border 6 in *01 mm. Border with inner edge indistinct* striae 
coarse, irregular. 
Habited. — Springfield deposit, Barbados (Schmidt, Birth !) * 
Richmond, Va. (Schmidt) ; Cambridge deposit, Barbados (Kinker, 
O’Meara!) “Barbadoes” (Johnson !+ O’Meara); Bridgewater, 
Barbados (Johnson !).f 
C. anastomdsans, Gran., DenJc. Wien. Ah., 1884, p. 75. — Diam. *18 
mm. Central space hyaline, irregular. Markings unequal, varying 
from *002 to *02 mm. in length, and forming an irregular network 
of anastomosing costae. 
Grunow justly regards this as probably abnormal. He is inclined 
to associate it with C. oculus-iridis, or some allied species. 
Habitat. — Santa Monica deposit (Grunow). 
C. irregularis , sp. n. O. ? pacificus, J Cstr., Dial. Chall. Exped., 
p. 158, pi. viii. fig. 5 ; pi. xxii. fig. 1. — Diam. *087 mm. Central 
space absent. Markings polygonal, unequal, from 2J to 3 in *01 
mm.; smaller towards the border. Border distinct, about i of 
radius broad; the striae distant, evident, 4 to 5 in *01 mm. 
Distinguished from C. marginatus by the less robust irregular 
markings. Similar irregularities are found in G. antardicus, from 
Kerguelen. The affinity to Endidya, founded on the character of 
the border, as pointed out by Castracane, is remote. 
Habitat. — Pacific Ocean, H.M.S. Challenger (Castracane). 
C. luxuriosus, sp. n. — Diam. *205 mm. Surface slightly convex 
from the centre for about J of the radius, thence flat to the border. 
Central space absent. Markings 4-6-, mostly 6-, angled, 2J to 3 in 
*01 mm.; central papillse evident; a few large irregular areolae with 
a distinct median line scattered irregularly among the others, and 
forming an indistinctly defined band adjacent to the border, and 
* In the collection of Dr F. W. Griffin. 
t In the collection of Dr Greville. 
t Preoccupied by Grunow in 1884, for what he regarded a doubtful var. of 
• C. oculus-iridis. 
