1888 - 89 .] Mr John Battray on the Genus Coscinodiscus. 537 
circumference, small but distinct ; a circlet of more minute apiculi at 
the border absent. Border narrow. — (PI. I. fig. 3.) 
Habitat. — Eio Janeiro (Kitton !) ; * Peruvian guano (Macrae !). 
O. patellceformis. Grev., Trans. Micr. Soc. Lond., 1861, p. 80, 
pi. x. fig. 4. — Diam. *07 to *1 mm. Surface slightly convex. 
Central space and rosette absent. Markings polygonal, in contact 
and without order for about ^ of radius, thence obtusely angular, 
pearly, 4 in *01 mm., increasing slightly outwards and forming 
straight rows ; secondary suhconcentric rows also evident ; at the 
origin of the shorter rows are sharply defined, irregular, elongate 
hyaline spaces ; a narrow hyaline hand within the border. Border 
with a single row of granules* 4 in ‘01 mm. — C. detritus , Sch., Atl ., 
pi. lviii. fig. 15. 
In Greville’s specimen, the undulating concentric lines crossed 
by stronger radial costae — as shown in his figure — do not occur. 
Habitat. — Springfield deposit, Barbados (Hardman !).f 
C. oblongus. Grev., Trans. Micr. Soc. Lond., 1866, p. 4, pi. i. 
figs. 9, 10. — Elliptical or oval, major axis *07 to ‘145 mm., from 2-| 
to 3 times minor. Surface depressed at the centre. Central area 
roundly or elongately elliptical, with rounded granules irregular, or 
in rows parallel to the major axis. Markings round, granular, 
increasing slightly from the edge of the central area outwards, again 
decreasing towards the border ; at the semiradius 4, near the border 
6, in ‘01 mm. ; rows straight only along the major and minor axes, 
between these slightly curved towards the major axis. — Sch., Atl., 
pi. lxvi. figs. 10, 11 ; C. oblongus forma typica, Truan and Witt, 
Jeremie Diat., p. 14, pi. ii. fig. 16. 
Distinguished from C. pundatus by the presence of a central 
depression, the absence of a central space, and of oblique decussating 
rows near the border. 
Habitat. — Chalky Mount., Barbados (Firth !) ; Barbados (Weiss- 
flog! Deby! Hardman! Kinker ! Cleve ! Greville !) ; Springfield 
deposits, Barbados (Johnson! Firth! | Hardman); § Pacific Ocean, 
* In the collection of Herr E. Weissflog. 
t In the collection of Dr Greville. 
£ In the collection of Dr F. W. Griffin. 
§ In the collection of Julien Deby. 
