1888-89.] Mr John Rattray on the Genus Coscinodiscus. 465 
Habitat. — Baku Harbur, Caspian Sea (Grunow) ; Lamlash 
(Gregory) ; Woolwich (Walker Arnott, Van Heurck !). 
C. minor. Ehrb., Abh. Ber. Ak ., 1838, p. 129, pi. iv. fig. 12e. 
— Diam. *0225 mm. Markings polygonal, minute, decreasing 
gradually from the centre outwards ; at the centre 6, at the border 9 
to 10 in ’01 mm ; rows less regular, the oblique decussating rows 
curved but slightly towards the border. Apiculi minute, close to the 
border, in the intervals delicate strise. — Ehrb., ibid., 1839, p. 147, pi. 
iii. fig. 2; ibid., 1841, p. 371, pi. ii. 4. fig. 8; pi. ii. 6. fig. 17, pi. hi. 
fig. 3 ; Mikrog., pi. xviii. fig. 31; pi. xix. fig. 3; pi. xx. 1. fig. 28 ; pi. 
xxi. fig. 5; pi. xxii. fig. 7; pi. xxxiii. 14. fig. 4 (?); pi. xxxix. 2. fig. 
22 (?) ; Ehrb., Die ll te Deutsdi. Nordpolarf., 1869-70, Leipzig, 
1874, p. 455, pi. ii. figs. 20, 23; Ralfs in Pritch Inf., p. 831; 
Janisch, Abh. Sch. Ges. vdter., Cult., 1862, p. 4, pi. ii.A, fig. 6; 
Grun., Sitzungsb. naturw. Ges. Isis, Dresden, 1878, p. 28 ; Sch., Atl., 
pi. Iviii. figs. 39, 40 ; pi. lix. fig. 8, ( 9 ; pi. cxiii. fig. 10 ; Raben., Alg. 
Europ., Nos. 2261, 2481, 2487 (excl. C. minor , W. Sm., Syn. Brit. 
Diat., i. p. 23, pi. iii. fig. 36 = Melosira nivalis and C. minor, 
Anglor, non Ehrb. = C. decipiens, Grun.) 
The early figures of Ehrenherg are unsatisfactory, and may 
indicate more than one species. The rows of smaller markings are 
more irregular than in C. excentricus and C. sol. Distinguished 
from C. decipiens by the less rapid diminution of the markings 
outwards and the less evident apiculi. The Aegina valve figured by 
Schmidt (Atl., pi. cxiii. fig. 10) shows a transition to C. tumidus in 
the arrangement of the markings. 
Habitat. — Caltanisetta (Ehrenherg, Grunow, Schmidt) ; Oran, 
Zante; Aegina, Richmond; Norwich, Con. (Ehrenherg) ; Peruvian and 
Ichahoe guanos (Janisch) ; Cuxhaven, S. Domingo, Haiti, Cuba, Yera 
Cruz (Ehrenherg); Girgenti (Grunow) ; Table Bay (Schmidt), lat. 71° 
19' N., long. 11° 28' W., 1319 fms., in yellowish-grey mud ; lat. 73° 
16' N., long. 15° 48' W., 1300 fms., in fine dark brown mud; lat. 63° 
40' N., long. 5° 28' E., 569 fms., in fine light grey mud; lat. 74° 18' 
N., long. 19° 24' W., 13 fms. (Ehrenherg) ; Davis Straits, deep water 
(O’Meara !); Nancoori (Hardman !); Cumbrae and Lamlash (Dickie !); 
Humber (O’Meara !) ; marine deposit, Fiji Islands (Grove !) ; Aegina 
(Schmidt) ; Algeria (Arnott !) ; Springfield deposit, Barbados 
vol. xvi. 25/10/89 2 g 
