JEGA BICARINATA. 279 
the larger size of the inner division of the appendages 
at the sides of that part of the body, which is, moreover, 
somewhat truncated at its inner extremity, whilst its 
outer margin has a slight emargination near its extremity. 
The eyes are wide apart and occupy the posterior angles 
of the head. 
The upper antenne are scarcely longer than half the 
width of the head; the basal joint is large, flat, and 
square, the second joint produced along its anterior mar- 
gin so as partially to conceal the base of the third joint 
(when seen from beneath), which is slender and succeeded 
by a very short flagellum, consisting of five or six arti- 
culi; the lower antenne are about as long as the width of 
the head, and have three short thick basal joints; the 
fourth is longer than the third, and the fifth nearly as 
long as the fourth, but more slender, and is followed by 
a flayellum, consisting of twelve articuli; these organs 
are separated at the base by a scutellum-shaped labrum, 
arising from a transverse keel or epistome. At the sides 
of each segment of the pereion the coxe of the legs are 
developed as parts of the dorsal surface (epimera), and 
have their outer portion raised and curved so as to form 
elevated spines overlapping each other; the segments 
themselves are marked across the middle, or nearer the 
base, with a raised line; the four anterior segments of the 
pereion are of equal size. ‘The surface of the pereion 
is seen, under a strong magnifying power, to be entirely 
covered with very minute circular punctures, amongst 
which larger and more irregularly shaped ones are dis- 
posed without order. 
Our drawing is made from Dr. Leach’s original type 
specimen in the British Museum, to which his own ma- 
nuscript name is still attached. In this specimen the 
extremity of the tail is formed precisely as represented 
