270 
BRITISH ENTOMOSTRACA. 
plates, each sending off three long and one short plumose 
setae. Third pair of foot-jaws very large. Sternal fork 
small, with simple branches. Fourth pair of feet termi- 
nating in one long curved spine or claw, serrated on its 
inner edge, and one or two short ones at its base. Ap- 
pendages at inferior portion of last articulation of the 
thorax slender, simple. 
Hab. — Belfast Bay, W. Thompson, Esq. Taken from 
the turbot in March, July, and December ; from the Trigla 
pini (gurnard), the mackerel, and Lota molva in March 
and October ; from the Merlangus carbonarius in March ; 
the j Vagellus centrodontus in October ; and the plaice in 
March, October, and December ; the codfish in January; 
and the halibut in March. British Museum. 
2. Caligus rapax. Tab. XXXII, figs. 2, 3. 
Caligus rapax, M. Edwards, Hist. Nat. Crust., iii, 453, No. 6, 
t. 38, f. 9. 
Description . — Female . Carapace oval, considerably 
longer than broad, narrower at upper extremity, and broad 
posteriorly. Frontal plates prominent, and very large for 
the size of the animal, nearly straight in centre, or but 
very slightly notched. Lunules large. Antennae also 
exceedingly large for the size of the animal, the basal 
joint broad, and armed with ten plumose hairs or setae 
on its upper edge ; the terminal joint long, nearly the 
length of the basal joint, and furnished at its extremity 
with five or six sharp setae. 
Thorax not quite so long as carapace, and much 
narrower ; last joint obovate or pyriform, and slightly 
lobed at the posterior extremity on each side. Abdo- 
men about two thirds the size of the thorax ; longer than 
broad. 
Caudal plates of considerable size, and terminated by 
three stout long, and one short, plumose setae. Sternal 
fork with simple, sharp-pointed branches. Fourth pair 
