102 
S. 1. Smith — Crustaceans of the Atlantic Coast. 
taper distally more than in TI. microps , and the inner margin in each 
is armed with a series of twelve to eighteen slender spines, extend- 
ing almost to the tip, in addition to the long seta?, while in H. microps 
there is oidy a single spine near the base. The telson differs from 
that of H. microps in having the lateral margins incurved at the tips 
and each armed with eleven to sixteen spines, of which nearly all are 
on the distal half of the margin and all placed at nearly equal dis- 
tances from each other, none of the proximal ones being scattered 
from the series as in H. microps ; the terminal spine each side has no 
small spine at its base but stands entirely alone; the sinus of the 
terminal margin is broad and broadly rounded at the proximal end, 
its lateral margins are nearly straight instead of convex in outline, 
and there are only fourteen to twenty spines on the entire margin. 
All the specimens I have examined have been taken in August and 
September and a large proportion of the individuals are females car- 
rying eggs or young. The species was never found in abundance 
except hidden away inside dead bivalve shells, usually Mactras, 
dredged in 5 to 10 fathoms. As many as twenty were sometimes 
found in a single shell. The males and young were occasionally 
taken at the surface in the evening in Vineyard Sound. 
Mysis mixta Liljeborg. 
Mysis mixta Liljeborg, Hafs-Crustaceer vid Kullaberg, (Efversight af Kongl. Vetens- 
kaps-Akad. Forhandlingar, Stockholm. 1852, pp. 3, 6. — Goes, Crustacea decapoda 
Sueciae, GSfversight af Vet. Akad. Forhand., 1863, 175 (15). — G. 0. Sars, Under- 
sogelser over Christianiafjordeus Dybvandsfauna, 35, 1869 (extr. Nvt Magazin 
Naturvidenskaberne) ; Archiv for Mathematik og Naturvidenskab, Kristiania, ii, 
p. 344, 1877. 
? Mysis latitans Kroyer, Et Bidrag til Kundskab om Krebsdyrfamilien Mysidm, 
Naturliistorisk Tidsskrift, III, i, p. 30, pi. i, fig. 4. 1861. 
Massachusetts Bay!, off Salem, 1877 : 20 fathoms, gravel, August 
6, — more than 200 specimens: abundant, also in August, in 22 fath- 
oms, gravel; 33 fathoms, sand and mud; 33 fathoms, soft mud; and 
35 fathoms, mud and clay nodules : common in 48 fathoms, mud, 
August 13. Gulf of Maine!, off Cape Ann, 1877: common at 90 
fathoms, mud, August 14, and at 50 fathoms, mud, gravel and rocks, 
October 17. Off Cape Ann!, 54 fathoms, gravel and stones, 1873. 
Also abundant, in 30 to 50 fathoms, muddy and gravelly bottoms, at 
various localities off Cape Ann !, 1878. Casco Bay !, August, 1873 : 
six miles southeast from Seguin Island, 35 fathoms, mud ; about sev- 
enteen miles off Cape Elizabeth, 64 fathoms, mud; and about 
