S. I. Smith — Grtistaceans of the Atlantic Coast. 103 



twenty miles off, 68 fathoms, mud. Bay of Fund)^, 1864, — one spe- 

 cimen. '? Greenland (Kroyer, — 31. 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™"' 

 long, a few, however, are females, from 20 to 25"^"' 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 ap])arently indicates that the species is an annual like M. 

 mixta. 



Mysis stenolepis Smitii. 



? 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 Fisli 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. Vineyai'd 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 algae, 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 

 Kam 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 stef7ole2ns, and scarcely nine times in 

 mixta), and nearly the whole outer margin of the scale is concave in 

 outline in stenoleins, while in mixta it is nearly straight, or even 

 slightly convex toward the base, Avhere 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 



