230 
BRITISH ENTOMOSTRACA. 
sharp-pointed beak (t. XXVII, f. f. 2 a, b ) and has 
near its junction with the first thoracic ring, on each side, 
a short, curved, sharp spine. 
The eye is single, in the male fixed upon a short peduncle 
(f. 1 g\ and projecting forwards and slightly downwards ; 
in the female sessile. “ It is of a beautiful dark-brown 
colour, with a shade of purple ; a circular space at the 
extremity is colourless, and sparkles brilliantly.” * 
The thorax is elongated, and consists of six segments, 
the last of which is narrower than the others, truncated, 
and terminates on each side in a point. Antennae long, 
about two thirds the length of the whole body. They 
are composed of numerous articulations, about twenty-five 
in number, each provided with one or more short setae. 
In the male the right antenna alone is provided with the 
swelling and hinge-joint. The swollen part is particularly 
large, and club-shaped, “ and running up through the 
centre of the swelling may be seen a muscle, which goes 
to be attached to the hinge-joint/ ’f 
The antennules (f. 1 ci) consist of a single branch, 
which is divided into three joints, the terminal joint 
being broad, and furnished with several long setae. 
The basal joint sends off from its internal side a small, 
slender twig, which is provided at the extremity with three 
or four setae. The labrum or lip is well developed, and 
consists of a projecting semi-oval plate, and two lateral 
lobes of considerable size. 
The mandible (f. 1 b) is in form of a strong plate, fur- 
nished with five stout teeth on its internal extremity, and 
having a rather large, palpiform branch from its upper 
edge, divided into two smaller branches. Each of these 
is formed of two articulations, the terminal one giving off 
at its extremity several long, plumose setse. The jaws 
are only rudimentary organs. 
The foot-jaws are three pairs in number. The first 
* Goodsir, loc. cit., 339. “The peduncle of the eye is of a dark blue.” — 
Paterson, quoted by Templeton, loc. cit. 
t Ibid, ibid. 
