CARIDEA. 593 



mation respecting this peculiar genus; but we have to regret the 

 loss of the specimen by the disastrous wreck of the Peacock, in conse- 

 quence of which we are prevented from giving minuter details. 



The slender anterior pair of feet and stout second pair, with broad, 

 equal hands, show a close relation to Pontonia ; and this relation is 

 farther seen in the foliaceous form of the outer maxillipeds, a charac- 

 teristic observed to some extent in Pontonia, and more complete in 

 Gnathophyllum. The abdomen is flexed after the third segment 

 nearly as in Hippolyte, and is somewhat abruptly narrower posterior 

 to this segment. 



HYMENOCERA PICTA. 



Rostrum longiusculum, in carapacem posticd productum, serratum. Seg- 

 mentum abdominis tertium posticb obluso-triangulatum. Antennae, 

 anticai breves, basi parce longiore quam rostrum, flagellis dimidio basis 

 brevioribus, flagello foliaceo breviter spatulato, altero tenuissimo, bre- 

 viore. Antennas external corpoi-e longiores, lamind basali rostro lon- 

 giore. Manus pedis secundi trapezoidalis, lata, oblonga, apice latior et 

 truncata, dorso recta, angulis rotundata, digito brevi, extus serrulato. 

 Maxillipedes externi oblongi, articulo secundo oblongo, tertio lato, trape- 

 zoidali, vix oblongo. 



Beak rather long, continued in a crest on carapax. Third abdominal 

 segment obtuso-angular behind. Inner antennae short, base slightly 

 longer than beak, branches not half as long as base, the foliaceous 

 one short spatulate, the other shorter and very slender; second 

 pair longer than body, basal scale longer than beak. Hand of 

 second feet broad, oblong trapezoidal, broadest at apex and truncate, 

 dorsal margin straight, angles rounded, finger short, serrulate with- 

 out. Exterior maxillipeds oblong, second joint oblong, third broad 

 trapezoidal, hardly oblong. 



Plate 39, fig. 3 a, animal, natural size , b, main branch of exterior 

 maxillipeds, enlarged; c, extremity of first legs, magnified four dia- 

 meters. 



Coral reefs of Raraka, one of the Paumotu Islands. 



149 



