12 Oscar Sund. [Nr. 6 



which I have seen carry at least 2 and sometimes as many as 



5 spines. 

 3. The comparative lengths of the joints of the 4th and 5th pereio- 



pod in Smith's species do not correspond with those found in 



the present species. 



Therefore I think it is not justiflable to use the name P. 

 princeps for the European species, for which I propose the name 

 P. principalis having regard of the great similarity between the 

 two forms. 



The distribution of P. principalis is shown on the chart fig. 1. 

 The occurrences in Sognefjord and also at Øxsund (E. of the Lofoten 

 isles, about 6772° N.) are indicated outside the coast only to make 

 the signs distinct from the black land-colour. 



From West Greenland (65° 14' N, 55° 42' W), from the Ice- 

 land ridge (61° 44' N, 27° 0' W) and from Denmark Straits (64° 

 42' N, 26° 40' W) I have seen single small specimens (C = 17, 

 10 and 14 mm. respectively), but from considerations which will 

 be set forth under the next species I regard it as extremely doubt- 

 ful whether they should be referred to that or to the present 

 species. The same may be said with regard to the other small 

 specimens enumerated above in which the carapace (C) is shorter 

 than 20 mm. but as they were captured in areas where no speci- 

 mens of P. tarda have been caught, it may be reasonable to ascribe 

 them to P. principalis. 



Kemp (1910, p. 46) states that according to the avaiiable in- 

 formation P. principalis is restricted to the bottom, but this is 

 not always the case, for the Danish and Norwegian catches were 

 often made in midwater. Even the two specimens from the Sogne- 

 fjord were tåken by the "Michael Sårs" in pelagic appliances. This 

 shrimp seems to lead a pelagic life in depths of 250 metres and 

 more, perhaps down to 1000 metres. But the records are still too 

 few to form any definite opinion on the matter. From its colour 

 one might perhaps infer that it frequents the same water-layers as 

 other red animals in our seas, for instance, the Norway Haddock 

 which is known from the investigations of the "Michael Sårs" to live 

 pelagically in the Norwegian Sea between 50 and 400, mostlv 100 

 and 200 metres. 1 ) A similar blood-red colour is found in the pelagic 



*) See Murray and Hjort: "The Depths of the Ocean". London 1912 

 Page 646—648. 



