1888 — 89 .] Mr John Rattray on the Genus Coscinodiscus. 493 
1844, p. 205; S. microtetras ,* Ehrb., Mon. Ber. Ak., 1855, p. 302; 
S. micropentas ,* Ehrb., ibid , 1855, p. 302 ; S. microhexas * Ehrb., 
ibid., 1855, p. 302; not S. trinitatis, Ehrb., ibid., 1844, p. 88; 
Ralfs in Pritch. Inf., p. 833, pi. xi. fig. 36, as indicated in the 
second edition of Habirshaw’s Catalogue, §' Symbolophora. 
By Grunow this species is brought near C. subtilis, but it is 
readily distinguished from the latter by the central star and the 
absence of apiculi. Symbolophora acuta, Ehrb., from Hollis Cliff, 
Virginia, of which hut a fragment is figured (. Mikrog ., pi. xxxiii. 
15. fig. 21), probably belongs to the present species. S. euprepia, 
Ehrb., from Licuare River, coast land Mozambique, remains a 
nomen nudum , but may come here (see Ehrb., Mikrog., p. 228), 
Small specimens of C. symbolophorus approach C. excentricus. 
Habitat. — Nottingham deposit, Mors deposit (Cleve ! Grunow) ; 
Simbirsk Polirschiefer (Ehrenberg, Grunow) ; Kekko, Szakal and 
Szent Peter deposits (Pantocsek) ; Eranz Josefs Land (Grunow); 
pancake ice, Antarctic Ice Barrier, and sounding of 190 fms., lat. 
78° 10' S., long. 162° W.; sounding 270 fms., lat. 63° 40' S., long. 
55° W. (Hooker) ; Ananino deposit (Grove ! Linker ! Hardman !);f 
Lumfiord, Jutland (Hardman !) ; Bermuda tripoli (Greville !); 
Oamaru deposit (Grove ! Marshall !) ; Ananino deposit (Rae ! 
Deby !). 
C. stellaris. Roper, Quart. Jour. Micr. Sci., 1858, p. 21, pi. iii. 
fig. 3. — Diam. ‘075 to 1 mm. Surface slightly convex. Markings, 
around the centre 5 or 6 large areolae, at subequal distances apart, 
and tapering towards both ends, elsewhere scarcely visible, 16 to 
20 in *01 mm., angular, most evident towards the centre, the rows 
forming fasciculi, those in each fasciculus parallel to the radial row 
at its middle. — C. stellaris, var. Cstr., Diat., Chall. Exped., p. 155, 
pi. iii. fig. 2 ; C. stellaris, var. fasciculata, Cstr., Diat., Chall. 
Exped., 1886, p. 158, pi. v. fig. 9. 
The colour when dry is brownish. Castracane’s Antarctic frustule 
seems to differ only in having four markings at the centre. 
Transitional forms to C. symbolophorus occur. 
Habitat. — Caldy, Pembrokeshire (Roper ! Rev. J. Guillemard) ; 
* Nomina nuda , probably identical with S. tetras , S. pentas, S. hexas. 
t In the collection of Julien Deby. 
