/S. I. Smith — Crustaceans of the Atlantic Coast. 9Y 



tooth and the tiagelliform portion is composed of fifteen or sixteen 

 segments. 



The abdomen is mnch narrower than the carapax and tapers only 

 slightly ; the first four segments are subequal in length, the fifth a 

 little shorter, and the sixth a fourth longer than tl)e fifth. The tel- 

 son (Plate XII, figure 2 c) is as long as the sixth segment, narrow, 

 triangular and twice as long as the width at base; the lateral mar- 

 gins are wholly unarmed and are suddenly expanded laterally near 

 the base, but are nearly straight from this expansion to the tip. In 

 the dorsal surface there is a deep median sulciis extending the whole 

 length, and from this the surface slopes down each side to the lateral 

 margin which is strongly upturned throughout. The extremity 

 (figure 2 d) is very narrow, truncated in a straight line and armed 

 Avith a median pair of slender spines of which the outer one is much 

 shorter and more slender than the inner, which is itself about two- 

 thirds as long as the space between the bases of the outer spines. 



The inner lamella of the uropods (Plate XII, figure 2 (/) reaches 

 only a little beyond the tij) of the telson, is expanded at the base for 

 the reception of the acoustic apparatus, but beyond this is narrow 

 and linear in outline ; both margins are furnished with long ciliated 

 setae which are nearly twice as numerous on the inner as on the outer 

 edge, and, in addition, the inner edge is armed beneath with a small 

 spine at the base of each seta. The outer lamella is nearly a third 

 longer than the inner, fully six times as long as broad, the greatest 

 breadth being near the middle of the length, and both margins are 

 regularly, though slightly, curved inward and each furnished with 

 about equally numei'ous seta?. 



The bases of all the pleopods in the male are rectangular in out- 

 line, and are very stout and muscular. The inner rudimeutaiy ramus 

 in the first pair of pleopods (Plate XII, figure 1 «) is soft, membrana- 

 ceous, and about a third as long as the outer ; the tei-minal portion is 

 slightly swollen, and rounded at the extremity ; and the lamellar 

 appendage projecting outward from near the base, and correspotid- 

 ing to that upon the same ramus of the succeeding pleopods, has 

 three or four hairs at the truncated tip and about the same number 

 of shorter ones on the upper edge. The outer ramus in the first pair 

 is, like the same ramus in the succeeding pairs, slender, much longer 

 than the base, and composed of about fourteen segments. The inner 

 rami of the second to the fifth pair of pleopods are similar to the 

 outei", except that they all have the lamellar appendage near the base, 

 like that upon the rudimentary ramus of the first pair, and usually 



Trans. Conn. Acad., Vol. V. 13 February, 18T9. 



