1888 - 89 .] Mr John Rattray on the Genus Coscinodiscus. 565 
hyaline. — Grun., Bot. Centralbl ., Bd. xxxiv. Nos. 2, 3, p. 35. — (PI. 
i. fig. i.) 
The central space and surrounding band are similar to those of 
C. asteromphalus, var. pabellanica , Grun., but the markings of the 
latter are quite distinct. I agree with Mr Grove that this species 
cannot be assimilated to C. perforatus , var. cellulosa, as stated by 
Grunow. 
Habitat. — Oamaru deposit (Grove !) ; Cambridge deposit Bar- 
bados (Johnson !).* 
C. umbonatus. Greg., Trans. Roy. Soc. Edin ., 1857, p. 500, pi. 
x. fig. 48. — Diam. *13 mm. Surface with central portion convex 
for about f of radius, sharply defined, thence almost flat to the 
border. Central space absent; rosette distinct, *0075 mm. broad. 
Mark areolate, subequal, 4 in. *01 mm.; close to the border 
submoniliform rows, distinct; the secondary oblique rows less 
obvious. — Jan. Abh. Schl. Ges. vdier. Cult., 1861, pi. ii. fig. 5, 
1862, p. 5. 
The radiating lines between the markings noted by Janisch are 
not found in the type. 
Habitat. — Lamlash (Gregory!);* Peruvian guano (Janisch). 
C. Weissjlogii. Sch., Atl., specimen plate (Einladung zur 
Subscription), 1874, fig. 5. — Diam. '0375 mm. Surface with 8 
submarginal bullations having the peripheral portion most prominent. 
Central space circular, obscure, a distinct rosette of 3 areolae meeting 
at its middle. Markings minute, 12 to 14 in *01 mm., rows straight; 
no primary rays corresponding to the bullations, surface scabrous. 
—(PL I. fig. 25.) 
This species is, in the opinion of Kitton, a Melosira. In the 8 
submarginal bullations it shows affinity to the Injlati section of the 
genus Aulacodiscus. 
Habitat. — New Zealand deposits (Kitton!); Samoa (Schmidt). 
C. theskelos, f sp. n. — Diam. *13 mm. Surface bearing a number 
of subradial curved or flexuous distinct lines, simple, or once dicho- 
tomous, and uniting around the centre to form a sharply curved 
* In the collection of Dr Grevillo. 
+ 0e <TKeXos, wonderful. 
