428 



BULLETIN OF THE BUREAU OF FISHERIES 



C. Near Lurcher Shoal, April 12, 1920, station 



20101 (fig. 120): 



Diatoms moderately abundant. 

 *Choetoceras atlanticum dominant. 

 *Ch. criophilum dominant. 

 *Ch. decipiens dominant. 

 *Ch. laciniosum dominant. 



Chsetoceras debile. 



Ch. diadema. 

 *Ch. seiraoanthum. 

 *Ch. scolopendra. 

 *Ch. sociale S. 

 *Coscinodiscus radiatus. 



Lauderia glacialis. 

 *Rhizosolenia semispina. 

 *Thalassiosira decipiens. 



Th. gravida. 

 *Tb. hyalina. 

 *Thalassiothrix nitschioides. 



Th. longissima S. 



D. German Bank, April 15, 1920, station 



20103. s6 



Diatoms very abundant. 

 *Chaetoceras contortum dominant. 

 *Ch. debile dominant. 

 *Ch. decipiens dominant. 

 *Cb. laciniosum dominant (with en- 

 docysts). 



*Biddulphia aurita. 

 *Cha?toceras atlanticum. 

 *Ch. criophilum. 

 *Ch. densum. 

 *Cb. diadema. 



D. German Bank, April 15, 1920 — Continued. 



*Ch. didymum. 

 *Ch. scolopendra S. 

 *Coscinodiscus lineatus. 



Coscinosira polychorda. 



Lauderia glacialis. 

 *Pleurosigma longum S. 

 *Rhizosolenia semispina. 

 *R. setigera. 



*Thalassiosira decipiens. 

 *T*h. gravida. 



Th. nordenskioldi. 

 *Thalassiothrix longissima. 

 *Th. nitschioides. 



E. German Bank, June 9, 1915, station 10290: 



Diatoms in medium abundance. 

 *Rhizosolenia semispina dominant. 

 *Chostoceras decipiens abundant. 



♦Actinoptychus undulatus. 



Chsetoceras contortum. 



Ch. debile. 

 *Ch. diadema. 

 *Ch. laciniosum. 

 *Coscinodiscus asteromphalus. 

 *Navicula directa S. 

 *N. lata S. 

 *Nitschia seriata. 

 *Pleurosigma normanii S., 

 *P. stuxbergii S., 

 *Rhaphoneis surirella S., 

 *Rhizosolenia alata. 

 *R. styliformis. 



Thalassiosira sp.? 



7. — Western Basin abreast of Massachusetts Bay 



B. April IS, 1920— Continued. 



*Thalassiosira nordenskioldi abundant. 



A. February 23, 1920, stations 20049 and 20058: 



Diatoms very scarce. 

 Coscinodiscus sp. ? dominant. 

 Chsetoceras decipiens. 

 Ch. atlanticum. 

 Ch. criophilum. 



B. April 18, 1920, station 20115: 57 



Diatoms moderately abundant. 

 *Choetoceras atlanticum dominant. 

 *Ch. decipiens dominant. 

 ♦Rhizosolenia semispina dominant. 

 '• At a neighboring station (20104) Doctor Mann also lists * Actinoptychvs undulatus, * Ch.itoceras sehacanthum, and * Paralia 

 sulcata. 



s7 A station (20114) in the center of the basin that same day adds the following species, verified by Doctor Mann: Chsetoceras 

 c riophilum, Ch. didymnm, Ch. furcellaium, Ch. teres; Rhizosolenia alata; Thalassiosira gravida, Thalassiothrir nitschioides; also Ch. 

 densum and Ch. contortum in another sample from station 20115. 



*Biddulphia aurita. 



Chsetoceras densum. 



Ch. contortum. 



Ch. teres. 

 *Ch. scolopendra. 

 ♦Rhizosolenia setigera. 

 *Skeletonema costatum S. 

 *Thalassiothrix longissima. 



' Ch.itoceras sehacanthum, 



