2 DR P. P. C. HOEK ON THE 



at which several hundred specimens of the one, and upwards of fifty of the 

 other, species were collected, it is even probable that — the same fishing appara- 

 tus (trawl) being used — one specimen was overlooked either remaining between 

 the meshes of the trawl or clinging to the rope. The nature of the animals, 

 with their long and numerous legs, each furnished with a claw, favours this 

 suggestion. The only specimen which remains as inhabiting both areas is 

 Nymphon grossipes, Oth. Fabr. : it is represented by eight specimens, four of 

 which are from the cold water area, and four from the warm water area. 



Comparing these facts with those furnished by the cruise of the " Knight 

 Errant" (1880), of the " Voringen " (1876 and 77-78), and of the " Willem 

 Barents " (1878 and 1879), and also with what is known about the Pycnogonids 

 of the North American coast (for which knowledge we are much indebted to 

 the studies of Mr E. B. Wilson), we have made the following table, from 

 which those species are excluded which have hitherto been only once 

 observed : — 



Name of the Species. 



Area in which 



H. M.S. 'Triton' 



caught it. 



Area in which 



the 



'KnightErraut' 



caught it. 



Area in which 

 G. 0. Sars 

 caught it. 



Does it 



inhabit the 

 Arctic Sea ? 



Does it 

 inhabit the 

 Atlantic near 

 the N. Ameri- 

 can coast ? 



Nymphon rdbustum, Bell, 



Cold 



Cold 



Cold 



Yes 



No 



„ macronyx, G. G. Sars, . 



Cold 



Cold 



Cold 



? 



No 



„ Stromii, Kroyer, . 



Cold 



Both 



Cold 



Yes 



Yes 



„ hirtipes, Bell, 



Warm 



... 



Cold 



Yes 



Yes 



„ macrum, Wilson, . 



Warm 







No 



Yes 



„ longitarse, Kroyer, 



Warm 





Warm 



Yes 



Yes 



„ grossipes, Oth. Fabr., 



Both 



Cold 



Cold 



Yes 



Yes 



„ serratum, G. 0. Sars, . 







Beth 



Yes 



No 



Colossendeis proboscidea, Sab. spec, 



Cold 



Cold 



Cold 



Yes 



No 



„ angusta, G. 0. Sars, . 



Cold 





Cold 



7 



Yes 



I'allene malleolata, G. 0. Sars, 



Warm 





Both 



2 



No 



Pallenopsis tritonis, n. sp., 



Warm 







No 



Probably 



From this table the following conclusions may be deduced : — 



1. The species which inhabit the cold area in the Atlantic occur also in the 

 Arctic Ocean (N. robustum, C. pi'oboscidea) ; those which have notyet been observed 

 in the Arctic may be expected to be found there (N. macronyx, C. angusta). 

 They are not found near the American coast, or only at a very considerable 

 depth (Colossendeis angusta at a depth from 810 to 1242 fathoms). 



