460 
Proceedings of Royal Society of Edinburgh. [sess. 
rows straight, fasciculate, those in each fasciculus parallel to the 
central row ; apiculi evident, inserted at inner edge of submarginal 
hand at intervals of *01 to *0125 mm. Border sharply defined, 
narrow, striae obscure, 12 to 14 in ’01 mm. (PI. II. fig. 10.) 
Habitat. — Straits of Macassar, recent (Grove !). 
C. ovalis , Bat tray. Cestodiscus ovalis , Grev., Trans. Micr. Soc. 
Lond ., 1865, p. 49, pi. v. fig. 9. — Elliptical or diamond-shaped, with 
angles obtuse. Major axis ’0625 to *1 mm., 1J to 1 J times minor. 
Central space absent. Markings towards the centre rounded 6, 
at about -f radius angular 8, on a sharply defined zone adjacent to 
the border punctiform, 12 in *01 mm.; rows radial, straight, the 
secondary oblique, decussating rows most evident on the median 
portion, interspaces most evident towards the centre ; apiculi pro- 
minent at intervals of about *0125 mm., inserted at inner edge of 
marginal band. 
In the Nancoori deposit, from the Nicobar Islands, as well as in that 
of Bichmond, Va., are very similar specimens, but possessing a distinct 
pseudonodule, and to these Grunow has given the name Actinocyclus 
dllipticus (Van Ileurck, Syn. Diat . Belg ., pi. cxxiv. fig. 10). The 
specimen figured by Witt from the Archangelsk Polirschiefer ( U . d. 
Polirscliief. von Archangelsk-Kurojedowo im Gouv. Simbirsk , 1885, 
p. 23, pi. viii. fig. 11), as Cestodiscus ovalis , var.? an Actinocyclus ? 
is to be associated with this species of Grunow, the pseudonodule 
being quite distinct. 
Habitat. — Moron deposit (T. G. Stokes ! Hardman !). 
§ III. Excentrici, Pant., Fossil. Bacil. Ung ., p. 72. 
Central space and rosette absent. Markings angular, decreasing 
gradually or more rapidly from the centre outwards ; radial rows 
obscure, oblique decussating rows evident, frequently somewhat 
curved towards the border; apiculi only near border, sometimes 
absent. 
C. minuens, Battray. C. decrescensf Cstr., Diat. Chall. Exjped ., 
p. 159, pi. xii. fig. 14. — Diam. T15 mm. Markings polygonal, de- 
creasing from the centre to the border, towards the centre 2, towards 
Name preoccupied by Grunow. 
