282 HGIDA. 
the tail, which is emarginate. The body is elongate-ovate, 
and convex, the eyes large and nearly meeting on the 
crown; the upper pair of antenne are not longer than the 
head, with a flagellum composed of about twelve articula- 
tions, the two basal joints very broad (the second obliquely 
emarginate), with the flagellum affixed on its hinder angle. 
The coxze of the legs attached to the anterior segments 
of the pereion are subquadrate and marked with straight 
elevated ridges; these are represented in our upper right- 
hand figure as seen on the underside of the body, show- 
ing the base of the three fore legs on the left side. 
The branchial plates on the underside of the body (as 
represented in our lower left-hand figure) scarcely ex- 
tend beyond the middle of the terminal segment; they 
are all of nearly equal size, the upper or outer pair not 
covering the whole or even the following pair. The 
lateral appendages also, when folded up, scarcely extend 
beyond the lateral margins of the terminal segment, the 
truncated extremity of each inner division uniting and 
leaving a triangular space uncovered at the extremity of 
the tail; the outer division of these lateral appendages is 
considerably smaller than the inner, and elongate-ovate 
in form, pointed at the tip, with the outer edge armed 
with spines arranged in transverse rows. 
The typical specimen of this species described by 
Leach was contained in Sowerby’s collection from Scot- 
land, and Mr. Gregor has sent it to us from the Moray 
Frith, and there are others now in the British Museum 
from Belfast, presented by Colonel Portlock. 
The late Mr. W. Thompson, of Belfast, also obtained 
it from Belfast Market, where it was found among Car- 
rickfergus oysters, at the end of March, 1839, and also 
from a cod-fish brought to the same market in February, 
1841. 
