364 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
seta on the posterior side of the first joint. The caudal lamina (pi. 27, 
fig. 6) has five spines on each plate, that decrease successively in length 
toward the posterior angle. In this character this species is more 
like S. Jervis than like S. capsula. 
Habitat .— A single female found in the dredgings from “Fish 
Hawk” station 7723 in the western portion of Vineyard Sound. 
In all its characters S. americana is more closely allied to the Euro¬ 
pean S. capsula than to other described species. 
Sarsiella zostericola sp. nov. 
PI. 28, fig. 7-18. 
Shell of male (pi. 28, fig. 7) subquadrate, obliquely truncate behind, 
greatest height somewhat anterior to the middle, equal to seven 
tenths of the length; ventral margin nearly straight but very slightly 
sinuous; dorsal margin highly convex centrally; posterior margin 
widely and obliquely truncate, forming distinct angles at its junction 
with the adjacent margins. The anterior extremity is bluntly rounded, 
the lower side rising at an oblique angle from the bottom of the anten¬ 
nal sinus, which is shallow, with the lower edge very gently convex. 
Surface of the shell at either side raised, the central portion having 
ridges at either side uniting anteriorly; at the ventral portion is a 
depressed area bordered by the lateral ridge and a broadly arcuate 
one situated dorsal to it. The rest of the shell surface is divided into 
a large anterior and a small posterior area by a ridge extending from 
the middle of the arcuate one to the dorsal edge of the posterior 
margin. The three depressed areas are nearly smooth and irregu¬ 
larly punctate. The antennal sinus and the whole ventral border 
are thickly set with long curved hairs. The anterior end has a few 
hairs and the posterior margin has a long one at the dorsal angle and 
one long and two short ones toward the ventral angle. 
Seen from above (pi. 28, fig. 8) the greatest width is slightly behind 
the middle. 
Antennulae of the male (pi. 28, fig. 9) have the first joint consid¬ 
erably longer than the second, the former without setae, the latter with 
one annulated seta toward the distal portion of the front margin. 
There is an annular depression suggesting another joint at the distal 
portion of the second; third and fourth joints subequal, the third 
