8 



KR. BONNEVIE. 



[REP. OF THE "MICHAEL SARS" NORTH 



Geographical distribution. 

 If my understanding of the synonymy 

 is correct P. diversa like P. reticulata, 

 seems to be a widely distributed species, 

 which has been found scattered in the 

 Indo-Australian and Atlantic oceans within 

 a zone between 40° N. and 30° S. (Pelse- 

 neer, Meisenheimer). It has been found 

 in the Mediterranean (Monterosato, 

 Oberwimmer), and along the European 

 (Locard, Pelseneer) and American coasts 

 (Dall). The results of the "Michael Sars" 

 Expedition prove the existence of P. 

 diversa in the Northern Atlantic up to 

 latitude 46° 58' N. (St. 90). As will be 

 seen from the table this species was not taken among 

 the surface plankton, but came mainly from a depth of about 

 1000 metres. It is of interest to note the conformity of 

 its distribution with the extension of a water-layer with a 

 temperature of about 6° — 8° C. and a salinity of 35—35-5 %o 



Station 



56 



58 



62 



64 



66 



88 



90 



Date 



••/e— l, /s 



ll /e— l3 /e 



2 %— 2l /6 



"As 



26 /<s 



18/7 



21/, 



Position w ' 



36° 53' 



29° 47' 



37° 37' 



29° 25' 



36° 52' 



39° 55' 



34° 44' 



47° 52' 



39° 30' 



49° 42' 



45° 26' 



25° 45' 



46° 58' 

 19° 6' 



Depth in m. 

 0— 50 

















50— 100 

 100— 250 



— 



1 



— 



— 



— 



— 



— 



250— 500 



— 



— 



— 



— 



— 



— 



— 



500- 750 



1 



— 



2 



— 



— 



— 



— 



750—1000 



— 



— 



— 



— 



3 



— 



1 



1000—1250 



10 



— 



1 



18 



— 



1 



— 



1250-1500 



— 



— 



7 



3 



— 



— 



— 



Number of individuals of Peraclis diversa. 



(see textfig. 37). With regard to P. brevispira Pelseneer, 

 Fowler (1906, p. 15) has arrived at quite similar results, 

 namely that it is "a member of the lower epiplankton" 

 and that it probably "ranges also in the mesoplankton 

 as low as the zone of 1000—750 fathoms". 



on 



t. 



Fig. 4. Radula-teeth of Pencils trtacantha. m.t, l.t, r.t as in textfig. 2. 



