490 
Proceedings of Royal Society of Edinburgh . [sess. 
Distinguished from C. radiatus by the fasciculate arrangement 
of the markings. 
Habitat. — Simbirsk (Grunow, Grove !); Ananino deposit (Grove ! 
Kinker! Rae ! Deby !); Archangelsk-Kurojedowo (Schmidt, Cleve !). 
C. symmetricus. Grev., Trans. Micr. Soc. Land ., 1861, p. 68, 
pi. viii. fig. 2. — Diam. *075 to *175 mm. Central space small, 
rounded, of diam. broad, sometimes absent. Markings subpearly; 
round or subangular, granular, 4 in *01 mm., subequal or slightly 
smaller at the border ; interspaces hyaline ; rows straight, fasciculate, 
those composing a fasciculus parallel to that at its centre ; around 
the border a narrow hyaline clear space, irregular on its inner side, 
sometimes bearing a few isolated granules. Border striae evident, 
6 in - 01 mm. — Excl. C. symmetricus , Sch., Atl ., pi. lvii. figs. 25-27 ; 
Grun., Denk. Wien. Ak ., 1884, p. 81. 
Narrow hyaline radial spaces sometimes, in larger valves, run 
outwards for some distance from the central space. Quite distinct 
from C. subtilis in the size and arrangement of the markings. C. ? 
clypeus, Ehrb. ( Mikrog ., pi. xi. fig. 6), from Bilin deposit, Bohemia, 
is too minute for identification. The fragments show rouud 
granular fasciculate markings with hyaline interspaces. Ehrenberg 
did not define the species, and regarded it as probably a fragment of 
Campylodiscus clypeus. The figure may represent a small piece of 
Coscinodiscus symmetricus , Grev. 
Habitat. — Cambridge deposit, Barbados (Johnson ! Greville ! 
Firth !); Manilla (Firth !); Newcastle deposit, Barbados (Firth !); 
“Barbados” (Kinker !). 
C. planiusculus, sp. n. — Diam. *0825 mm. Surface flat. Central 
space rounded, indistinct, about of diam. broad. Markings 
rounded or oval, with long axis radial; outlines faint; central 
papillae evident ; about 3 \ in -01 mm., subequal, on a distinct band 
around the border, about i to of radius broad, moniliform ; rows 
fasciculate, those in each fasciculus parallel to that at its middle. 
Border crenate, a minute dark speck at each indentation at intervals 
of about *005 mm. — Janisch, Gazelle Exped ., taf. vi. fig. 12. (PI. I. 
fig. 22.) 
Differs from C. subtilis in the shape of the markings, the monili- 
