I. '08. 



42 



Irish distributioji. 

 off the Irish coast :- 



A single specimen only has been found 



Hclga. 



S.R. 212— 6/5 /'05.— 51° 54' N., 11° 57' W. 370-411 fathoms. 

 Trawl. Temperature at 350 fathoms 9-82° C, salinity 

 35 •28°/^^— One, 65 mm. 



This is the most southern locality from which the species 

 has been recorded in East Atlantic waters. 



Vertical range. — P. tarda is not confined to the bottom, 

 but is frequently found swimming at intermediate depths. It 

 has been recorded from 60 and 525 fathoms off the Norwegian 

 coast and during the Sw^edish Arctic expedition was caught 

 in a vertical net lowered to 1,640 fathoms (Ohlin). A single 

 specimen has been found at the surface in the North Sea 

 (Meinert), and off the East Coast of the United States it has 

 been trawled in 140-175 fathoms (Smith). V\ ^ 



Pasiphae princeps, Smith. §^ 



PI. IV, figs. 1-7. 



Pasiphae princeps, Smith, 1884, PL v, fig. 2. 

 Pasiphae princeps, Smith, 1886. 

 Pasiphaeia princeps, Faxon, 1895. 

 Pasiphaea princeps, Eathbun, 1904. 



Several specimens trawled in deep water off the w^est coast 

 of Ii eland are referred to this species. They differ from the 

 original description in certain particulars, but subsequent 

 authors have shown that in most of these very particulars a 

 considerable range of variation exists ; there can be little doubt 

 that these Irish specimens, the first that have been found in 

 the East Atlantic, represent a European race of P. princeps. 



This species is very closely related to Pasiphae tarda, but 

 attains to a much larger size. P. tarda does not appear to 

 reach a length of more than 10 cms., while the type of P. 

 princeps was more than twice this size. 



Specimens of P. tarda and princeps of 40 mm. in length, or 

 more, may be separated thus : — 



P. tarda. 



1. Rostrum a procurved 

 post-frontal spine , strongly 

 ascendant from the dorsal 

 carina of the carapace and an- 

 teriorly concave. 



2 . Carapace , measured in the 

 mid-dorsal line, very little, if 

 at all, more than half the 

 length of the abdomen (ex- 

 cluding the telson). 



P. princeps. 



1. Rostrum a post-frontal 

 elevation of the dorsal carina 

 of the carapace, not strongly 

 ascendant, and almost in- 

 variably distinctly sinous an- 

 teriorly (figs. 4-6). 



2. Carapace, measured in the 

 mid-dorsal line, considerably 

 more than half the length of 

 the abdomen (excluding the 

 telson). 



