314 HISTORY OF BRITISH CRUSTACEA. 



Caligus centrodonti, Baird. — Carapace, in the female, 

 obovate, narrower in front; frontal plates deeply notched 

 in the middle. Thorax much smaller than carapace, last 

 joint squareish, lower margin crescentic. Abdomen very 

 small, quite concealed by ovarian tubes when filled with 

 ova. In the male the carapace is large, the thorax much 

 smaller. 



Hab. Found on the tail and fins of the Tagellm centro- 

 doniis, Dublin. 



Gen. 173. LEPEOPHTHEIRUS* Nordmann. 



Thorax of two distinct joints. Frontal plates without 

 small sucking-discs on their under surface. Fourth pair of 

 feet slender, of one branch, and serving for walking. 



Lepeophtheirus Stromii, Baird. (Plate XIX. fig. 2.) 

 — Carapace, in the female, oval ; frontal plates not very pro- 

 minent ; length of body, about half an inch ; horny tuber- 

 cles on hind part of thorax, large and simple. Male much 

 smaller than the female. 



Hab. Berwick : on salmon. 



Lepeophtheirus pectoralis, Mtiller, sp. — Carapace, in 



* From A.e7ros and <pdeip. 



