1888-89.] Mr John Rattray on the Genus Coscinodiscus. 573 
C. mossianus .* Grev., Trans. Alter. Soc Lond. 1865, p. 25, 
pi. iv. fig 22. — Diam. *135 mm. Surface flat to about the semi- 
radius, thence sloping gently to the border. Central space minute. 
Markings pearly, obtusely quadrangular, those in the outermost 
hand concavo-convex with large faint rounded central dots, increas- 
ing from the centre to about J of the radius to 2 or 2J in ’01 mm., 
thence decreasing uniformly to the border to 3 in ’01 mm., 
irregular around the centre, the rows separated by clear lines. 
Habitat. — Cambridge deposit, Barbados (Johnson !).t 
C. gemmifer. Ehrb., Mon. Ber. Ak., 1844, p. 201. — Diam. 
about '06 mm. Central space circular, hyaline, about ^ of diam. 
broad. Markings rounded, conspicuous, about 5 in ’01 mm., 
decreasing from the central space outwards ; towards the border 
punctiform, interspaces hyaline; rows straight. — Ehrb., Mikrog , 
pi. xxxv. a. 22. fig. 3. 
By Ehrenberg, compared with Pyxidieula gemmifer a, Ehrb., 
from Virginia. Rot to he united to C. elegans , Grev., as suggested 
by Pantocsek, since in the latter the radial rows are more crowded. 
Allied to C. cycloteres , Cstr., but distinguished by the less uniform 
markings, and to C. aetinochilus , Ehrb., where, however, the radial 
rows are also more numerous. 
Habitat. — Ice Barrier, Antarctic, lat. 78° 10' S., long. 162° W.; 
Sounding, 190 fathoms, lat. 78° 10' S., long. 162° W.; ex Saljod, 
lat. 66° S., long. 157° W.; Sounding, 270 fathoms, lat. 63° 40' S., 
long. 55° W. (Hooker) ; Monterey Stone (Cleve !). 
Var. camjpechiana, nov. C. gemmifer, var., Grun. MS. — Diam. 
•0375 mm. Central space round, i to ^ of radius broad, punctate. 
Markings most prominent near the central space ; indistinct 
towards the border, the interspaces minutely punctate. 
Habitat. — Campeachy Bay (Weissflog !). 
C.ftagrans, sp. n. Sch., Atl., pi. lvii. fig. 46. — Outline hexagonal, 
with angles obtuse and sides slightly convex. Diam. about ’03 mm. 
Central space distinct. Markings rounded, granular, about 5 in 
* Dedicated to Mr Moss of Lancaster, the friend and fellow worker of Mr 
Johnson. 
t In the collection of Dr Greville. 
