1888 - 89 .] Mr John Rattray on the Genus Coscinodiscus. 597 
Mr Grove, resembles C. dubiosus , but the delicate hexagonal 
markings are rather larger ; the surface is dotted over with small 
spots (apiculi ?), each standing in the middle of a rosette of 5 to 6 
areolae ; there is a submarginal circlet of apiculi ; the rows are 
straight, radial and non-fasciculate ; there are small subulate inter- 
spaces at the origin of the shorter rows, and the border is striated. 
§ VII. Elaborati. 
Valves elongately elliptical. Markings rounded or granular ; 
the rows chiefly disposed with relation to the major axis. 
C. naviculoides. C. ? naviculoides , Tru. and Witt, Jeremie Diat ., 
p. 14, pi. ii. fig. 10. — Rliomboidal. Major axis *0875 to ’ll mm., 
3 to 3J times minor. Surface flat. Central space and rosette 
absent. Markings pearly, decreasing somewhat from the centre 
outwards about 4 in *01 mm.; round and irregular at the centre, 
obtusely angular, and in faint rows subparallel to the major 
axis towards the more acute extremities ; irregularly transverse or 
oblique decussating secondary rows sometimes evident, on a sharply 
defined narrow band adjacent to the border punctiform, and in 
more evident oblique decussating rows. Border narrow ; striae 
obvious, 8 to 10 in *01 mm. 
Distinguished from C. lewisianus by the more rhomboidal out- 
line, and the closer arrangement of the markings, which are disposed 
in less evident rows. 
Habitat. — Jeremie deposit (Truan and Witt); Monte Gubbio 
(Grove !). 
C. paleaceus, Rattray. Stoschia ? jpaleacea , Gran. Van Heurck, 
Syn. Diat. Belg ., pi. cxxviii. fig. 6. — Elongately and irregularly 
elliptical, frequently with shallow lateral undulations. Major axis 
•0425 to *1 mm., from 4 to 8 times the longest transverse axis. 
Surface almost flat ; central space and rosette absent. Markings 
polygonal, 6 to 7 in ‘01 mm. Subequal, without order or in 
obscure rows ; around the border a distinct band of areolae. 
Habitat. — Nancoori (Hardman !); * Naparima (Kitton). 
* In the collection of Julien Deby. 
