S. I. Smith — Crustaceans of the Atlantic Coast. 
103 
twenty miles oil', 68 fathoms, mud. Bay of Fundy, 1864, — one spe- 
cimen. ? Greenland (Kroyer, — M. latitans). Iceland (G. O. Sars). 
Finmark (Goes), Lofoten Islands ! and Christiania Fiord (G. O. Sars). 
Baltic (Liljeborg, et al.). 
All the American specimens examined were taken between August 
4 and October 17 ; most of them are young, between 12 and 20 mm 
long, a few, however, are females, from 20 to 25 mm long, with nearly 
fully developed ovigerous lamellae, but none of them carrying eggs. 
This seems to show that the breeding season is during the winter, 
and it apparently indicates that the species is an annual like M. 
m ixta. 
Mysis stenolepis Smith. 
t Mysis spinulosus Gould, Report on the Invertebrata of Massachusetts, 1st edit., p. 
333, 1841 (not of Leach). 
Mysis stenolepis Smith, Report on the Invertebrate Animals of Vineyard Sound, 
Report, U. S. Commissioner of Fish and Fisheries, part i, p. 551 (257), pi. 3, fig. 
12, 1874. 
New Haven!, Connecticut, among eel-grass. Noank!, Connecti- 
cut, among eel-grass, etc., 1874. Vineyard Sound! and Buzzard’s 
Bay !, among eel-grass, and also dredged in a few fathoms among 
algfe, 1871, 1875. Gloucester!, Massachusetts, 7 to 10 fathoms, 
sand and red algte, 1878. Casco Bay!, 1873: Portland Harbor, 
among eel-grass ; Quohog Bay, among eel-grass ; between Overset 
Island and Peak’s Island, 18 fathoms, rocks and sponges; and off 
Ham Island, 18 fathoms, mud. Halifax!, Nova Scotia, 1877: Outer 
Harbor, 16 to 21 fathoms, fine sand, stones, and red algae; also, 18 
fathoms, mud and fine sand. 
This species, although very closely allied to M. mixta is certainly 
distinct. The antennal scales in stenolepis are much longer and pro- 
portionally narrower toward the base than in the allied species (in 
the full-grown female the greatest breadth being contained in the 
length about twelve times in stenolepis , and scarcely nine times in 
mixta), and nearly the whole outer margin of the scale is concave in 
outline in stenolepis , while in mixta, it is nearly straight, or even 
slightly convex toward the base, where the concavity is usually great- 
est in stenolepis. The two distal segments of the antennular pedun- 
cle are nearly equal in length in stenolepis , the penultimate being 
only very slightly the longer; while in mixta the penultimate is fully 
a third longer than the ultimate and absolutely longer than in steno- 
lepis (the length of the penultimate segment being contained in the 
