330 AMPnil'ODA NORMALIA. 



podunde obliquely truncate, the distal extremity carrying numerous 

 auditory cilia ; tiagellum consisting of a single long nan'ow arti- 

 culus. Inferior antenniu four-jointed, having the iirst three joints 

 subequal, the fourth short and terminating in a single hair. First 

 pair of gnathopoda having the carpus broad, but not anteriorly pro- 

 duced, the inferior margin being coarsely, and the anterior margin 

 finely serrated ; propodos serrated along the inferior margin ; 

 dactylos short, not capable of reaching the anterior extremity of 

 the carpus. Second pair of gnathopoda longer than the first, the 

 carpus having the infero-anterior margin produced as long as the 

 propodos, minutely serrated along the anterior and inferior mar- 

 gins ; propodos coarsely serrated along the inferior margin ; dactylos 

 short, capable of antagonizing with the apex of the produced caqjus. 

 First two pairs of pereiopoda having the mera and carpi subequally 

 long ; propoda one-third the length of the carpi ; dactyla short. 

 Third pair of pereiopoda having the anterior margin of the basos 

 not serrated, the five distal joints being but half the length of the 

 basos, and the ischium articulating postero-subapically vdih it. 

 Foiu'th pair of pereiojioda having the basos posteriorly arcuate and 

 anteriorly excavate, the distal extremity obtusely rounded, the 

 ischium articulating with the posterior margin near the centre ; 

 the remaining joints being about one-third the length of the basos, 

 and having the flexible margin of the propodos reversely serrated. 

 Fifth pair of pereiopoda membrtmous, long, and shghtly curved, 

 terminating in a small tubercle that represents the undeveloj)ed 

 portion of the limb. Anteiienultimate pair of pleopoda having the 

 outer margin of the peduncle serrated ; rami foUaceous, equal, and 

 distally serrated : penultimate pair having the peduncle short ; 

 rami equal, with the margins entire : ultimate pair having the 

 peduncle short ; outer ramus pointed, serrated on the inner margin ; 

 inner rami fused with the peduncle, and having the inner margin 

 sen-ated alternately coarse and fine. Telson obtusely pointed. 

 Length 1 inch. 



Hub. Found in the stomach of a shark in the Pacific Ocean, in lat. 

 26° 27' S., long. 99° W. Coast of Malabar (Capt. Dumimier, 183(J). 



These specimens belong to the collection entrusted to me from the 

 Jardin des Plantes. 



2. Platyscelus serratus, n. s. (Plate LII. figs. 10 & 11.) 



Female. — Cephalon transversely ovate. Pereiou much distended ; first 

 segment nearly as long as the second, but much narrower than the 

 cephalon. Picon considerably narrower. Superior antennae ha\'ing 

 the peduncle truncate, the inferior distal extremity bearing a bunch 



