1888 - 89 .] Mr John Rattray on the Genus Coscinodiscus. 521 
gonal; towards the centre 6 to 9, gradually decreasing towards 
the border to 9 or 10 in '01 mm.; secondary oblique rows evident; 
minute, subulate spaces at origin of the shorter rows. — Grun., 
Denk. Wien. Ak., 1884, p. 72; Janisch, Gazelle Exped ., taf. v. 
fig. 9 ; taf. vi. fig. 4. 
This species was formerly associated by Grunow with C. radiolatus , 
Ehrb., a species that cannot be determined with certainty. The 
specimens referred to from Macassar Straits are more convex towards 
the centre, and have been authenticated by Grunow. 
Habitat. — Monterey and Barbados deposits (Grunow) ; South 
Sea (Grunow) ; Los Angelos (O’Meara !) ; Macassar Straits (Grove !). 
Yar. kerguelensis. Grun., Denk. Wien. Ak ., 1884, p. 73. Diam. 
•047 mm. Markings towards the centre 6, at the border 9 in ‘01 mm.; 
close to the border a circlet of minute apiculi. 
Habitat. — Kerguelen (Grunow). 
C. subaidacodiscoidalis , sp. n. Sch., Atl, pi. lvii. fig. 8. — Diam. 
*0425 mm. Surface convex. Central space absent, rosette minute. 
Markings angular, 6 to 8 in *01 mm., decreasing gradually towards 
the border ; secondary oblique decussating rows evident ; apiculi, 
six large, with a slight median constriction inserted some distance 
from the border at subuniform intervals. Border narrow, hyaline, 
sharply defined. 
This species in its general characters approaches Aulacodiscus 
concinnus , Kitton, but there are no primary rays, and the processes 
are reduced to stout apiculi. 
Habitat. — Baldjik (Schmidt). 
C. B alley i, Rattray. Cestodiscus Bailey i, H. L. Sm., Amer. 
Quart. Jour. Microscopy , 1878, p. 16, pi. iii. fig. 8. — Diam. *04 to 
*0925 mm. Central space small, rounded, indistinct, bearing 
isolated granules. Markings 12 in ‘01 mm.; rows radial, straight; 
distinct hyaline subulate spaces opposite origin of shorter rows, 
secondary oblique rows evident ; apiculi distinct, at wide intervals 
inserted a short distance within border ; inner layer of valve with 
a clear central space surrounded by a zone of closely disposed costae 
6 in ’01 mm., outside the latter a second broad hyaline zone 
