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BULLETIN OF THE BUREAU OF FISHERIES 
11. — Geobges Bank, east end 
A. March 11, 1920, station 20066: 
Diatoms not plentiful. 
*Coscinodiscus asteromphalus domi- 
nant. 
*Actinoptychus undulatus. 
♦Chsetoceras atlanticum. 
*Ch. criophilum. 
*Ch. decipiens. 
Ch. densum. 
*Ch. didymum. 
*Coscinodiscus concinnus. 
*C. excentricus. 
*C. oculus-iridis. 
*C. radiatus. 
*Melosira sulcata. 
♦Rhaphoneis surirella. 
*Thalassiothrix nitschioides. 
B. April 16, 1920, station 20109, southeast edge 
of bank. 
Diatoms very abundant. 
♦Chsetoceras debile dominant. 
*Ch. decipiens dominant. 
*Ch. laciniosum dominant. 
♦Chsetoceras atlanticum. 
*Ch. contortum. 
*Ch. criophilum. 
*Ch. densum. 
*Ch. diadema. 
*Ch. didymum. 
*Coscinodiscus asteromphalus. 
C. sp.? 
B. April 16, 1920 — Continued. 
*Fragilaria oceanica. 
Lauderia glacialis. 
♦Nitschia seriata. 
♦Pleurosigma stuxbergii. 
♦Rhizosolenia semispina. 
*Skeletonema costatum. 
♦Thalassiosira gravida, abundant. 
*Th. nordenskioldi, abundant. 
*Th. hyalina. 
♦Thalassiothrix longissima. 
*Th. nitschioides. 
C. April 17, 1920, northeast part of bank, 
station 20111 (fig. 122): 
Diatoms in medium abundance. 
♦Chaetoceras atlanticum. 
♦Coscinodiscus 60 dominant. 
♦Chsetoceras decipiens. 
*Ch. densum. 
♦Coscinodiscus concinnus. 
*C. heteroporus (?) 
D. July 23, 1914, station 10224: 
Diatoms abundant. 
♦Guinardia flaccida dominant. 
♦Rhizosolenia shrubsolei notably abun- 
dant. 
♦Actinoptychus undulatus. 
*Cerataulina bergonii. 
♦Navicula gelida. 
Rhizosolenia semispina. 
*R. styliformis. 
12. — Georges Bank, western end 
A. February 22, 1920, station 20046: 
Diatoms abundant. 
♦Chsetoceras sociale dominant. 
*Actinoptychus undulatus. 
Chsetoceras atlanticum. 
*Ch. criophilum. 
Ch. decipiens. 
♦Coscinodiscus crassus. 
*C. subbulliens. 
Eucampia zodiacus. 
♦Guinardia flaccida. 
Leptocylindrus sp.? 
♦Navicula gelida. 
♦Nitschia sp.? abundant. 
♦Rhizosolenia imbricata. 
B. May 17, 1920, station 20128: 
Diatoms few on surface, abundant at 
20 meters. 
*Chsetoceras sociale dominant. 
♦Chsetoceras atlanticum. 
*Ch. decipiens. 
♦Coscinodiscus concinnus. 
*C. subtilis. 
♦Navicula gelida. 
♦Pleurosigma normanii. 
♦Thalassiosira decipiens. 
♦Thalassiothrix longissima. 
oo Doctor Mann states ‘‘fully 50 per cent of the diatoms are an intermediate form between C. asteromphalus and C. oculus- 
ridis, having the convexity and areolation of the former and the fineness and general delicacy of the latter. Indeed, Rattray and 
others look on C. oculus-iridis as not a valid species ” 
