552 REPOET OF COMMISSIONER OF FISH AND FISHERIES. 



The females differ but little from the males except in the usual sexual 

 characters. The figure, (Plate III, fig. 12,) made from a small female 

 specimen, does not properly represent the anterior margin of the cara- 

 pax. 



In life the young females are semi-translucent, a spot on each ocular 

 peduncle, the peduncles and inner flagella of the autennulte, the 

 antennal scale, the telson and caudal lamellae more or less blackish 

 from deposits of black pigment, while each segment of the abdomen is 

 marked with a rudely stellate spot of black. 



Large males of this species Avere found in the autumn among eel- 

 grass, at New Haven, Connecticut, and the youug abundantly in the 

 same situation in May. Young females were collected m abundance 

 during June and July, among the eel-grass in the shallow bays and 

 coves about Vineyard Sound, while adult females, with the marsupial 

 X)ouches filled with youug, were collected, at Wood's Hole, in abun- 

 dance, April 1, by Mr. Y. JS". Edwards. 



Mysis Americana. Smith, sp. no v. (p. 396.) 



Anterior margin distinctly rostrated, but only slightly projecting; 

 evenly rounded, the inferior angle projecting into a sharp tooth. An- 

 tennulae, in the male, with the densely ciliated sexual appendage similar 

 to that in M. vulgaris of Europe ; the outer flagellum nearly as long as 

 the body, the inner slightly shorter. Antennal scale about three-fourths 

 as long as the carapax, about nine times as long as broad, tapering 

 regularly from the base to a very long and acute tip ; both margins 

 ciliated. Appendages of the fourth segment of the abdomen in the 

 male similar to those in JIL vulgaris. The outer ramus is slender and 

 naked, and its pair of terminal stylets are equal in length, slender, curved 

 toward the tip, and the distal half armed with numerous short setfe • 

 the ultimate segment of the ramus itself is little more than half as long as 

 the stylets, the penultimate segment four or five times as long as the 

 terminal. Inner lamella of the appendages of the sixth segment about 

 as long as the telson, narrow, slightly broadened at the base, and taper- 

 ing to a slender but obtuse point; outer lamella once and a half as long 

 as the inner, and eight times as long as broad, slightly tapering, the ex 

 tremity subtruncate. Telson triangular, broadened at base, the lateral 

 margins slightly convex posteriorly, and armed with stout spines alter- 

 nating with intervals of several smaller ones; the tip very narrow, 

 truncate, armed with a stout spine each side, and two small ones filling 

 the space between their bases. Length 10 to 12""". 



This species was found, in April, at Beesley's Point, New Jersey, in 

 pools, upon salt-marshes, and at the same locality the stomachs of the 

 spotted fioiinder were found- filled with them. Professor D. 0. Eaton 

 found it in great abundance among sea- weeds, &c., just below low- water 

 mark, at Kew Haven, Connecticut, May 5, 1873. It was also taken in 

 the dredge, in 4 to fathoms, at New Haven, Connecticut, and in 25 



