514 Proceedings of Royal Society of Edinburgh. [sess- 
and C. marginatus , Ehrb., on the other. Yan Heurck’s figure is 
from a photograph by Dr Woodward. 
Habitat. — Moron deposit (Greville ! Grunow) ; Sta Monica 
deposit (Rae!); Szent Peter and Dolje deposits (Pantocsek); 
sounding, lat. 3° 1' S., long. 33° 50' W., H.M.S. Challenger 
(Rae !); Yirginia (Greville !); Sta Maria deposit (Grove !). 
Var. minor , nov. C. obscurus, var. ? Sch., Atl., pi. lxi. figs. 17, 
18. — Diam. *05 to *06 mm. Markings smaller, 3 in *01 mm. 
Border striae longer. — Grun., ibid., 1884, p. 74. 
Habitat. — Moron deposit (Greville !). 
C. radiatus. Ehrb., Abh. Ber. Ah., 1839, p. 148, pi. iii. figs. 1 a-c 
(excl. d ). — Diam. *0675 to *18 mm. Central space absent. Mark- 
ings polygonal, 2 to 2J in *01 mm., subequal from the centre for 
about f of radius, thence decreasing sometimes to 6 in *01 mm., in 
inconspicuous radial sometimes subfasciculate rows, central dots 
faint. — Ehrb., Mihrog ., pi. xix. fig. 1 ; pi. xxii. fig. 3 ; pi. xxxiii. 
13. figs. 2, .2*; pi. xxxiii. 16. fig. 6; pi. xxxv. a. 17. fig. 6 (excl. 
pi. xx. 1. fig. 27 ; pi. xxi. fig. 1); Ralfs in Pritch. Inf., p. 831, 
pi. xi. figs. 39, 40; Sch., Atl., pi. lx. figs. 5, 6, 9 ; pi. lxii. fig. 18; 
pi. lxv. fig. 8; Grun., Denk. Wien. Ah., 1884, p. 71 ; pi. iii. (c), 
figs. 4, 7 ; in H. L. Smith, Diat. Spec. Typ ., No. 99 ; Cleve and 
Moll., Diat., Nos. 57, 114, 155, 164, 207, 211, 215, 257; Raben., 
Alg. Europ., Nos. 2263, 2437, 2487 ; Coll., Kiitz. Diat., No. 902 ; 
C. caspius, Ehrb., Abh. Ber. Ah., 1872, p. 170, pi. xii. fig. 14 ; 
C. argus, Sch. (non Ehrb.), Atl., pi. lxi. fig. 13 (excl. C. radiatus, 
Weisse, Bull. Acad. Imp. St Petersb., 1868, p. 122, pi. i. fig. 25 ; 
and C. radiatus, Bail, Amer. Jour. Sci ., xlii. 1842, p. 95, pi. ii. 
fig- 14). 
Schumann ( Schrift . Phys. Oeh. Ges. Konigsberg, 1867, p. 61) 
proposed to break up this species restricting C. radiatus for 
those forms in which the markings are angular, and decrease 
from the centre outwards from about 6 to 7J in *01 mm. 
Other forms from the Baltic, with round markings and fine short 
furrows within the border, 16 J in *01 mm., he named C. vicinus ; 
but the definition of this last species, which is not accompanied 
by a figure, is inadequate, and the name may be abandoned. 
