36 BULLETIN OF THE 



armed with only two very long, slender, and plumose setae, which arise near 

 together from the under side. 



It appears to be a much smaller species than either Norvegicus or spinosus, 

 the largest males being scarcely 25 mm. in length and the largest females about 

 36 mm. 



This species was taken in great abundance, in 51 to 155 fathoms, off Block 

 Island, in 1880 and 1881, by the U. S. Fish Commission. The specimen figured 

 is from the Fish Commission collection, Station 873, 100 fathoms. 



Pontophilus gracilis, sp. nov. 



Plate VII. Figs. 3 - 3\ 



This species is very much more slender and has much larger eyes than any 

 other species of the genus known to me. It is represented in the collection by a 

 single specimen, which is possibly immature, but, judging from the structure 

 of the appendages of the first and second somites of the abdomen, is a female. 



The carapax is nearly twice as long, along the dorsal line, as broad, slightly 

 carinated, and so thin that the branchiae are readily seen through it. The 

 rostrum is about two sevenths as long as the rest of the carapax along the dorsal 

 line, very slender, and the lateral teeth scarcely a third of the way from the 

 base to the tip. The dorsal carina is not distinct except where it rises into two 

 acute teeth directed forward, one on the gastric region and one on the anterior 

 part of the cardiac. There is a slight lateral carina in the middle portion of 

 the carapax, terminating anteriorly in a spine like those in the dorsal carina. 

 A little farther down upon the carapax and a little in front of the anterior 

 spine of the dorsal carina there is a small hepatic spine, making in all six 

 spines exclusive of those of the anterior margin. The orbit is very broad and 

 its outer border extends far forward and terminates in a slender spine, while 

 the similarly slender spine of the antero-lateral angle extends still farther for- 

 ward nearly or quite to a line with the tip of the rostrum. 



The eyes are very large and reach to about the tip of the rostrum ; the cornea 

 is oblique, somewhat compressed vertically, and its greatest breadth considerably 

 more than the breadth of the antennal scale. The peduncle of the antennula 

 scarcely reaches the middle of the antennal scale, and the lateral process from 

 the base of the first segment reaches to the distal extremity of the segment 

 itself ; the outer flagellum is slender and reaches to the tip of the antennal 

 scale ; the inner is about a third longer, but scarcely stouter, than the outer. 

 The antennal scale is about three fourths as long as the carapax exclusive of 

 the rostrum, about four times as long as broad, only very slightly narrowed 

 distally, and the tip evenly rounded. The distal segment of the peduncle is a 

 little more than half as long as the scale, and the flagellum is slender and 

 about twice as long as the carapax exclusive of the rostrum. 



The first and second maxillipeds are nearly as ' in P. Norvegicus. The ex- 

 ternal maxillipeds reach by the tips of the antennal scales by fully half the 



