S. I. Smith — Crustaceans of the Atlantic Coast. 
71 
G. O. Sars, nor 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, 26 to 41 fathoms, soft mud, 
common, 1877. Also otf Halifax !, 42 fathoms, tine 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 posterior 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, scarcely reaches the tips 
of the peduncles of the antennuhe, 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 
flagellum of the antenna, at least in adult males, is considerably 
longer than the body ; two males, 41 and 43 mm long, each have the 
flagella about 50 mm 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 spcci- 
