6 P. T. CLEVE, ON DIATOMS FROM THE AKCTIC SEA. 



The same form is also found in Scotland and on tlie coast 

 nf Germany (Helgoland Max Schulze). Coscinodiscus concin- 

 nus KoPER M. J. VI pag. 20 Pl. III fig. 12 seems only to be 

 a variety of C. centralis; at least I have observed on speci- 

 mens from Waijgats Ids. a row of spicula^ near the margin; 

 see also tlie preceeding paper on diat. from the sea of Java^ 

 pag. 5. 



7. Coscinodiscus subtilis Ehb (M. Gcol. Pl. XVIII fig. oG. 

 Kg. Bac. pag. 132. T. I fig. XI c). Finmarhen: Grötsnnd; 

 very rare. Greenland exeedingly common in mud taken at 

 great depths from Davis Strait and also < in the contents of 

 the stomach of Ctenodisens, dredged from the depth of 232 ftms. 

 51° 20' N 52° 25' W. (North West. Atlantic). The stomach 

 of the Ctenodiscus contained an enormous niimber of Cos. sub- 

 tilis and C. Oc. Iridis, but no other diatoms were found. 



The Cos. subtilis occurs aboundantly in the mouth'of 

 Elbe (Germany). 



8. Coscinodiscus Normannii Greg {GreviUe M. J. VII pag. 

 80 Pl. \I fig, 3). Davis Strait in mud from great depth 

 very rare. 



. 9. Coscinodiscus excentricus Ehb. {Kg. Bac. pag. 131. T. 

 r fig. 9). Spetsbergen: Kingsbay (60 fthms). Davis Strait. 

 Beeren Eiland in mud from 1200 fth dept. 



Var. lineatus (Cosc. lineatus Ehb. Kg. Bac. pag. 131 T. I 

 fig 10). Finmarken: Grötsund. Spetsbergen Hackluyts. Bee- 

 reen Eiland. (1200 fths. diam. 0,n4S — 0,06 m.]n., cellulcs eqvaL 

 12 — 14 in 0,0 2.5 m.m.). 



This species is widely distributed and found aboundantly 

 on the coasts of the North Sea and according to Grunnow in 

 New Zeeland, Cape of Good Hope, St. Pauls Ids., Tahiti 

 Honduras, Chili, Nicobaren Ids. 



10. Coscinodiscus nitidus Greg. (Diat. of Clyde pag. 499 

 T. X fig. 45) Some few specimens are observed in mud from 

 great depths in Davis Strait. This species is also observed 

 in Scotland (Greg) Auckland, Nicobaren Ids., Valparaiso (Gru- 

 now), West Indies (Cl). 



11. Thalassiosira Nordenskiöldii Cl. N. Sp. Cliar. Gen. 

 Thalassiosirre: Sideview circular, with a row of submarginal 

 spines; sculpture very minutely cellulär, cellules arranged in 



