108 



THE DEPTHS OF THE SEA. 



[chap. hi. 



Thorsliavn about noon, steaming east by south, so 

 as to cross the deep channel between Eaeroe and 

 Shetland. Our first two stations were on the Fseroe 

 plateau, at depths a little over a hundred fathoms, but 

 the third sounding, taken in the evening of the 24th 

 at a depth of 317 fathoms, gave a bottom temperature 

 of — 0°-9 C. ; we were therefore once more in the cold 

 current. Having kept the same course under easy 

 steam during the night, we took a sounding next 

 morning, lat. 61° 21' N., long. 3° 44' W., at a depth of 

 640 fathoms, with a bottom temperature of — 1°-1 C. 

 A haul of the dredge brought up rolled pebbles and 



Via. V2.—Pourtalssia jeffreysi, VfyviLLE Thomsos. Slightly enlarged.! (No. 64.) 



fine gravel with few animal forms, but among them 

 one of extraordinary interest, a large specimen of a 

 fine species of the genus .Pourtalesia, a heart -urchin, 

 one of whose congeners had been discovered by 

 M. de Pourtales in the gulf- stream explorations off 

 the American coast, and a second by Mr. Gwyn 

 Jeffreys near Eockall. The present example (Fig. 12) 

 was much larger than either of those previously 

 dredged, and it appeared to be specifically distinct. 



1 I have the pleasure of dedicating this interesting species to our 

 accomplished colleague, J. Gwyn .Jeflfreys, F.R.S. 



