OF ARTS AND SCIENCES. 205 



of larger primary tubercles arranged in horizontal rows across the 

 primary plates. Its outline is more rectangular anteriorly, and more 

 nearly vertically truncated. — Station 147, 1,600 fathoms; Station 

 156, 1,975 fathoms. 



Pourtalesia laguncula, A. Ag., nov. sp. 



This is very closely allied to P. miranda ; it is, however, more 

 bottle-shaped, comparatively broader at the anterior extremity, shorter, 

 with a wide anal snout and a more vertically truncated anterior ex- 

 tremity ; shorter actinal plastron, with broad fasciole round the anal 

 snout. This fasciole I did not detect in P. miranda, and as the unique 

 specimen is at present in the hands of Professor Loven I am unable to 

 give its position in that species. — Station 191, 800 fathoms ; Station 

 168, 1,100 fathoms; Station 232, 344 fathoms; Station, 244,2,900 

 fathoms. 



Pourtalesia carinata, A. Ag., nov. sp. 



This is a large species with a comparatively stout test, quite gibbous, 

 apex posterior, with its greatest breadth near the posterior extremity ; 

 largest primary spines on median interambulacral line of abactinal side 

 of test in the anterior and in the odd interambulacra ; rest of test 

 quite thickly covered with small secondary spines, increasing in size 

 towards the ambitus ; on the actinal side the plastron carries still 

 larger primary spines closely packed on the ridge of the actinal 

 keel. — Station 299, 2,160 fathoms ; Station 157, 1,950 fathoms. 



Pourtalesia ceratopyga, A. Ag., nov. sp. 



Test seen from above, triangular, with rounded apex formed by 

 anal snout and base with rounded corners and re-entering centre, as 

 well as re-entering sides. Seen in profile, the outline is rectangular, 

 with the anal snout projecting from the posterior extremity like a 

 knob. The actinal side is nearly flat, the abactinal outline somewhat 

 rounded posteriorly (apex posterior), while abactinal system is placed 

 nearer the anterior extremity, which also rounds off gradually. Seen 

 endwise, the outline is triangular, with rounded corners ; actinal groove 

 less pronounced than in the species of the P. miranda type. The test 

 is thickly covered by tubercles of nearly uniform size, irregularly 

 arranged, carrying short slender spines ; they are larger and carry 

 longer spines along the abactinal keel and on the sides of the actinal 

 groove. The color of the test, which is quite solid, is deep violet. — 

 Station 298, 2,225 fathoms. 



