Report on the Malacostraca, Pycnogonida and some Entomostraca. ßl7 



lies much farther to the south, namely about Cape Cod or for a few 

 species a little more to the north towards Newfoundland. The zoo- 

 geographical boundary-region here is one of the places, which has 

 the greatest economical importance in the whole world. "Chacun 

 connaît la richesse extrême en poissons du banc de Terre-Neuve. 

 La raison principale de cette abondance sur un point aussi restreint 

 est liée à la rencontre de deux courants à temperatures très différ- 

 entes. Un courant froid qui descend des côtes boréales de l'Amér- 

 ique rejoint, dans les parages de Terre-Neuve, le courant chaud 

 connu sous le nom de Gulf Stream, qui apporte des eaux chaudes 

 du golfe de Mexique. Au moment où les deux "fleuves" se rencontrent, 

 une grande partie des animaux habitués à l'eau froide boréale sont 

 tués par l'eau chaude du Gulf Stream, et réciproquement. Il s'en suit 

 qu'à la hauteur de Terre-Neuve il y a dans la mer une foule de cadav- 

 res d'animaux qui alimentent copieusement les poissons eurythermes 

 de cette région; ils y viennent en foule et y pullulent". (Joubin, Cours 

 d'Océanographie, Bull. Mus. Monaco, No. 45, 1905, p. 13 — 14). 



The boreoarctic littoral fauna contains a large number of species, 

 луЬ1сЬ seem on the whole to belong to the boreal region, but to be 

 eurytherm, so that they can also live under arctic conditions. An 

 exception, however, is Gammariis locusta, which grows largest in the 

 arctic seas. On the European side the southern boundary for most 

 of the species is at the Channel, but a few are also found as far to 

 the south as the Azores. On the American side the southern bound- 

 ary is mostly at Cape Cod. In his work on the Crustacea collected 

 by W. A. Herdman in Puget Sound, Pacific Coast of N. America 

 (Transact. Liverpool Biol. Soc, vol. 12, 1898, p. 270), Walker has 

 given a list of the Crustacea from the Atlantic with corresponding 

 species from the Pacific, and it is a remarkable fact, apparent from 

 the lists above, that a large number of Greenland boreoarctic littoral 

 forms are also found in the Pacific. For the sake of comparison 

 these species are brought together below; alongside each species is 

 noted under which group it has been mentioned. 



Hyas coarctatus (3E). Calliopius laeviusculus (3E). 



Chionoecetes opilio (ЗА). Leucothoe spinicarpa (3E). 



Nectocrangon lar (3B). Melita dentata (3E). 



Spirontocaris Fabricii (ЗА). Cercops Holboelli (3E). 



— macilenta (ЗА). Caprella septentrionalis (3E). 



— groenlandica (3B). Idothea metallica (3E). 



— Gaimardii (3E). Edotia nodulosa (3E). 



— turgida (3E). Phryxus abdominalis (3E). 

 Pandalus Montagui (3E). Bopyroides hippolytes (3E). 

 Opisa Eschrichtii (3E), 



