1888—89.] Mr John Rattray on the Genus Coscinodiscus. 545 
straight, secondary oblique decussating rows evident. Border 
narrow, sharply defined ; strise faint, 6 in *01 mm. 
Distinguished from C. apiculatus by the more delicate markings 
that are devoid of prominent central papillae, and by the distinct 
central space. 
Habitat. — 1 (Griffin !) ; Chincba guano (Schmidt). 
C. conformis, sp. n. Sell., Ail., pi. cxiv. fig. 4. — Diam. ‘2 mm. 
Surface somewhat depressed at the centre. Central space circular, 
about -Jg- of diam. broad, surrounded by an inconspicuous band of 
areolae subobsolete on their central side. Markings 4- to 6-angled, 
without puncta at the angles, increasing gradually to the semiradius, 
again decreasing to the border ; towards the central space 4y, at the 
semiradius 3^, at the border 5 or 6 in *01 mm.; central papillae 
indistinct ; delicate puncta at the origin of the shorter rows ; 
secondary oblique rows short, substraight, evident. Border narrow ; 
striae 8 in ’01 mm. 
Habitat. — Arica (Schmidt). 
C. josejinus. Grun., Denk. Wien. Ak., 1884, p. 75, pi. iii. (C), 
fig. 16. — Diam. ‘08 mm. Surface convex. Central space small, 
subcircular. Markings smooth, decreasing but slightly near the 
border, 7 to 8 in ’01 mm. Border striae delicate, 14 in - 01 mm., 
about -Jg- of radius broad, at its middle a sharp line concentric with 
the outer edge. 
Distinguished from C. radiosus, Grun., and C. fimbriatus, Ehrb., 
by the character of the border. 
Habitat. — Pranz Josef’s Land (Grunow). 
C. nobilis. Grun., Jour. Roy. Micr. Soc. Lond., 1879, p. 687, 
pi. i. fig. 1. — Diam. '375 to *54 mm. Central space distinct, 
hyaline. Markings minute, about 7 in ’01 mm., hexagonal towards 
the border, separated into obscure fasciculi by inconspicuous radial 
lines. — Cleve and Moll., JDiat., Nos. 145, 146, 162; C. regius , 
Grun., Sitzungsb. naturw. Ges. Isis., Dresden , 1878, p. 124. 
Sometimes mistaken for C. eoneinnus, but distinguished by its 
large central area and more distinct radial rows of markings. 
Habitat. — In Noetiluca, at Gorleston Pier, Suffolk, Harwich 
(Grunow !) ; Ascidia, Hull (Greville !) ; Hong Kong and Arafura Sea 
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