26 



Against the backdrop of extensive panoceanic distribution of many 

 of the Physosomata, just mentioned above, there are species whose dis- 

 tribution is confined to specific chmatic zones or localized regions in the 

 oceans. Thus, species found in the Pacific Ocean, according to the nature 

 of their area of distribution, can be divided into the following groups.^ 



1. Species inhabiting both cold-water"* and tropical regions of the 

 ocean: Lanceola sayana, L. loveni, L. pacifica, L. laticarpa, L. clausi, 

 Scypholanceola agassizi, Prolanceola vibiliformis, Chuneola paradoxa, 

 Microphasma agassizi, Mimonectes sphaericus, M. loveni, M. gaussi, 

 Scina incerta, S. borealis, S. spinosa, S. wolterecki, S. pusilla, Ctenoscina 

 brevicaudata, C. macrocarpa, Spinoscina spinosa. Only one of these 

 species (L. laticarpa) is not found beyond the limits of the Pacific 

 Ocean, the remainder having a panoceanic distribution. The absence of 

 P. vibiliformis in the Atlantic Ocean and C. macrocarpa in the Indian 

 Ocean, should probably be attributed to the inadequate study of the 

 deepwater faunas of these oceans. 



2. Species usually found in the northern part of Pacific and not 

 in its tropical regions, but found sometimes in the tropical regions of 



31 other oceans. In this group are included: Lanceola serrata, Mimonecte- 

 ola beebei, Scina stebbingi, S. rattrayi keilhacki.* Possibly, in the north- 

 ern part of the Pacific Ocean, these are represented by special forms, 

 differing very little from the typical but spatially separated forms. Nev- 

 ertheless, in the Atlantic and Pacific material of L. serrata, M. beebei, 

 and S. stebbingi, morphological differences were observed (Vinogradov, 

 1957). 



3. Species restricted in distribution to tropical regions: Lanceola 

 intermedia, L. felina, L. loveni grossipes, L. clausi pirloti, Metalanceola 

 chevreuxi, Mimonectes diomedeae, Proscina magna, Scina crassicornis, 

 S. curvidactyla, S. vosseleri, S. marginata, S. oedicarpus, S. tullbergi, 

 S. nana, S. excisa, S. lepisma, S. stenopus, and Acanthoscina acanthodes. 

 Practically all these species have a circumtropical distribution. 



4. Endemic North Pacific species whose distribution is associated 

 with waters of the North Pacific Ocean {Scina curilensis), waters of the 

 Sea of Okhotsk {S. wagleri), or finally, the abyssal zone of the Kuril- 

 Kamchatka Trench (Lanceola sphaerica, L. chelifera). 



5. The area of distribution of species restricted by cold-water Antarc- 

 tic regions: Paralanceola anomala and Mimoscina setosa. 



' Particularly rare forms, known from one or two reports, whose distribution is difficult 

 to judge with any degree of reliability, will not be considered here. 



" In referring to cold-water regions, we imply primarily northern ones, since the 

 deepwater fauna of high latitude in the southern hemisphere in the Pacific sector has 

 hardly been investigated. 



* Scypholanceola aestiva removed from list in Russian text by authors. — ^Eds. 



