S. I. Smith — Crustaceans of the Atlantic Coast. 97 
tooth ancl the flagelliform portion is composed of fifteen or sixteen 
segments. 
The abdomen is much 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 the 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 sulcus 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 
with 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 a) reaches 
only a little beyond the tip 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 numerous setae. 
The bases of all the pleopods in the male are rectangular in out- 
line, and are very stout and muscular. The inner rudimentary ramus 
in the first pair of pleopods (Plate XII, figure 1 a) is soft, membrana- 
ceous, and about a third as long as the outer; the terminal portion is 
slightly swollen, and rounded at the extremity ; and tlie lamellar 
appendage projecting outward from near the base, and correspond- 
ing to that upon the same ramus of the succeeding pleopods, lias 
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 
outer, 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. Acau., Vol. V. 13 February, 1879. 
