754 



CRUSTACEA. 



abdominal segments are as broad nearly or quite as the last thoracic 

 segment. The antennae are stout and flattened, and project either 

 side of the prominent front. 



The specimen is a dried one, and in some points the body may 

 have lost somewhat its natural shape. The projections of the first 

 thoracic segment either side of the head, are exceedingly short in the 

 specimen, though broad, and have the anterior margin straight trans- 

 verse, with the outer side a little revolute, and having an edge rising 

 upward from the anterolateral angle of the projection. 



Genus LIVONECA, Leach. 

 LlVONECA LONGISTYLIS. 



Corpus duplo longius quam latum. Segmenturn abdominis posticum 

 paulo transversum, bad latius, postice" obtusi-angulatum. Styli cau- 

 dales segmenturn caudate multum superantes, angulo basis interim 

 obtuso, ramis inoequis, lamellatis, intemo obliqul truncato, externo 

 obtuso, recto, longiore. Epimeroe breves, acuminata^, obtusce, segmenta 

 vix superantes. 



Body twice as long as broad. Last abdominal segment, shorter than 

 broad, broadest at base, obtuse-angled behind. Caudal appendages ex- 

 tending a little beyond apex of abdomen ; inner angle of base obtuse, 

 branches unequal, lamellar ; inner obliquely truncate, outer obtuse, 

 straight, longer than the inner. Epimerals short, acuminate, ob- 

 tuse, hardly reaching beyond their respective segments. 



Plate 50, fig. 3 a, dorsal view ; b, caudal appendage. 



Rio Janeiro ; found within the gills and on the body of an Ephip- 

 pus ; also, from the Sandwich Islands. 



Length, about one inch. Colour, pale yellowish. Head semicir- 

 cular in front; posterior angles projecting; eyes indistinct. Thoracic 

 segments subequal, first longest, not extending forward either side of 

 head. Claws of third pair of legs not smaller than on preceding pair; 

 of seventh pair a little smaller than the preceding, but leg scarcely at 



