/S. I. Smith — Crustaceans of the Atlantic Coast. 71 



G. O. Sars, uor Metzger refer to this early description, so that I allow 

 the species to stand for the present under Norman's name, 



Hippolyte macilenta Kroyer. 



Bedford Basin!, Halifax, Nova Scotia, 2G to 41 fathoms, soft mud, 

 common, 1877. Also oif Halifax !, 42 fathoms, fine sand ; 52 fathoms, 

 fine sand and mud; and 57 fathoms, mud and pebbles. Gulf of St. 

 Lawrence !, 30 to 70 fathoms, sandy and stony bottoms, 1872, 1873 

 (Whiteaves), Labrador ! (Packard). Greenland (Kroyer). 



This species was described by Kroyer from a single specimen and 

 I have noticed no mention of other specimens, except those of Packard 

 and Whiteaves above referred to. The species is very distinct from 

 the others of the genus known to me. Kroyer's description and fig- 

 ures apply well to medium sized females, but there is some individual 

 variation and the young differ very considerably from the adults in 

 the form of the rostrum. It is the most slender of our species, the 

 carapax being scarcely thicker posteriorly than in front, and its 

 greatest breadth only about an eighth of the length of the animal. 

 The appendages are likewise longer and more slender than usual in 

 the genus. In adults of both sexes the dorsum of the carapax is 

 evenly rounded the postei-ior two-thirds of its length and the rostral 

 carina rises abruptly from the anterior fourth. The rostrum is very 

 much shorter than the rest of the carapax, scai-cely reaches the tips 

 of the peduncles of the antennulte, is very much compressed, and 

 ascends so that the tip is considerably above the level of the dorsum 

 of the carapax, while the dorsal edge is strongly arcuate and dentate, 

 very nearly its entire length, with twelve to fifteen minute teeth, 

 which are crowded anteriorly but much more remote at the base and 

 on the carapax. The anterior portion of the rostrum is expanded 

 below and armed with one to four small teeth near the very slightly 

 prominent tip. In the young the rostrum is slender, nearly horizon- 

 tal, only slightly expanded vertically, terminates in an acute tip and 

 is armed with fewer teeth than in the adult, although there are at 

 least nine above and one below in all the specimens I have seen. 

 There are no supraorbital spines, but well-developed antennal and 

 distinct pterygostomian spines are present in all the specimens. The 

 fiagellum of the antenna, at least in adult males, is considerably 

 longer than the body ; two males, 41 and 43"'™ lo"g, each have the 

 flagella about 50™'" long. The telson is much more slender than 

 usual in the genus. In twenty specimens specially examined, there 

 were invariably three pairs of dorsal aculei, and in fourteen speci- 



