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. 



Hah. — 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 carhonarius in March ; 

 the Fayellus 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 kapax, M. Edtvards, 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. Fourtli pair 



