THE AMERICAN NATURALIST [Vol. XL VII 



66° S. Its temperature range is from 27° C. to 4°. 7 C. 

 8. ferox, on the other hand, is a warm-water species con- 

 fined, so far as known, to the epiplankton of the tropical 

 Indo-Australian region. Both species were taken during 

 the Siboga expedition, but, while 8. ferox was taken in 

 abundance from the surface, 8. planktonis was taken only 

 from the mesoplankton. There is no record of both hav- 

 ing been taken in the same hauls except in those made 

 with open vertical nets. 



E. HAM ATA AND E. FOWLEKI 



It is still an open question in my mind whether E. 

 foivleri is a valid species or merely a synonym for E. 

 hamata. Eitter-Zahony ('115) describes certain differ- 

 ences, but the characters used appear indicative of varia- 

 tion within the species rather than of constant specific 

 characters. If they should prove synonymous, then 

 Eukrohnia would be represented by only one species. 

 However, assuming their validity, then E. hamata would 

 be distributed in the mesoplankton of the Indian, Altantic 

 and Antarctic oceans, while E. fowleri is rarer and per- 

 haps more cosmopolitan, occurring in the Irish sea 

 between 200 and 1,100 fathoms, in the Bay of Biscay be- 

 low 325 fathoms, in the Malay Archipelago below 460 

 fathoms, and rarely in the open Atlantic below 500 

 fathoms. It might be added that E. hamata also occurs 

 in the epiplankton of the Arctic and Antarctic regions, 

 while E. foivleri always remains confined to the meso- 

 plankton. During the Plankton expedition the species 

 were taken together in only one closing-net haul made 

 between 500 and 600 fathoms, and only twice out of 18 

 open vertical hauls from a variety of depths. 



K. SUBTILIS AND K. PACIFICA 



K. subtilis is regarded as a eurythermal cosmopolitan 

 species ranging from 60° 12' N. to 29° 30' S. The tem- 

 perature corresponding to its capture varies from 30°. 8 



