756 



CRUSTACEA. 



LlYONECA LATA. 



Corpus latius, sesqui longius quam latum. Segmentum abdominis ulti- 

 mum dimidio thoracis latitudine, basi latius, postice arcuatum et non 

 angulatum nee emarginatum. Styli caudales abdominis exfremitatem 

 non superantes, ramis latis, apice rotundatis, paulo inoequis. Epi- 

 merce posticoe ultra segmentum paululo salientes et non attenuate, 



0btU8CB. 



Body one and a half as long as broad. Last segment of abdomen half 

 as broad as thorax, broadest at base, rounded behind, without an 

 angle or emargination. Caudal stylets not reaching beyond line of 

 extremity of abdomen, branches broad, rounded at apex, somewhat 

 unequal. Posterior epimerals but slightly salient beyond the ad- 

 joining part of thoracic segment, not attenuated, obtuse. 



Plate 50, fig. 5 a, animal, one and a half times the natural size ; b, 

 fourth, fifth, sixth, and seventh epimerals, left side, and part of at- 

 tached segments; c, caudal stylet. 



Sandwich Islands. 



Length of body, eleven lines. Like the specimens of the other 

 species, the body is distorted, owing to its position on the fish upon 

 which it was found. The head is subtriangular, and its greatest 

 breadth is about half that of the next segment. The posterior epi- 

 merals are the only ones that project beyond the segment adjoining, 

 and these project but slightly. The caudal segment is much nar- 

 rower than tergal part of last thoracic segment. 



Genus NEROCILA, Leach. 



One of the most striking characters, separating Nerocila from either 

 of the three preceding genera, is the different relative lengths of the 

 six posterior thoracic segments. In Livoneca, these segments are sub- 

 equal, as to length, the last being a little the shortest. In Cymothoa 



