CYMODOCEA TRUNCATA. 427 
The body is somewhat cylindrical, with the sides nearly 
parallel. The entire length of the animal is about two 
and one-fourth times the width of the middle of the 
body. The antenne are short, the inferior being about 
as long as the breadth of the head; the superior have 
the basal joimt (omitted in our upper left-hand figure) 
strongly punctured. The tail has the upper surface 
irregular and setose. The basal portion has the middle 
of the posterior margin extended backwards, and emar- 
ginate, with two small tubercles near the angles of the 
emargination. The large terminal joint has two large 
oval setose tubercles in the middle of the upper side, 
followed by a slightly convex lobe, on which the bristly 
setee are set in a diverging manner; and the extremity 
of the joint is armed with three flat truncated spines. 
The lateral appendages of the tail do not close as in the 
Spherome, so as to form a convex shield, but are carried 
obliquely upwards; the inner division is small and 
obliquely truncate, with the entire margin thickly set 
with strong bristles, and the outer division is consider- 
ably larger and oval in form, but with the outer angle 
subacute. The inner portion of this outer plate is par- 
tially folded when at rest beneath the inner plate. 
This species was taken by Montagu and Leach on the 
Devonshire coast; but very sparingly. The Rev. A. 
Norman dredged it in Lamlash Bay, in the Isle of Arran, 
and found it under rocks at low water at Herm; and the 
late Mr. W. Thompson took it in Belfast Bay, at Rock- 
port, in April, and Mrs. Hyndman on Cultra shore, in 
September, and Dr. Macintosh has sent it to us from 
St. Andrews. 
