C A R I D E A. 571 



the protuberance below. In our species, but four branchiae were 

 counted on either side of the thorax; none were attached to the fifth 

 pair of legs ; the leaflets were long linear. The abdomen posteriorly, 

 for the last three segments, is very narrow, the three anterior seg- 

 ments being very broad, and the fourth rapidly narrowing; the last 

 three were flexed upon the venter, and filled up the space left be- 

 tween the sides of the preceding segments. Eyes quite small, and 

 projecting only their diameters. Scales of the outer antennae partly 

 concealed beneath the front. Beak flat and short. 



The single specimen of this species collected by us, was lost at the 

 wreck of the Peacock. The drawings and descriptions were made 

 from the living animal. 



PONTONIA TRIDACNJE. 



Corpus depressum. Carapax nudus, leecis, paulo oblongus, rostro trian- 

 gidato, obtuso. Antennae internee perbreves, flagellis subcequis, artieulis 

 duobus precedentibus non oblongis. Squama antennarum externarum 

 basalis apicem rostri non superans; flagellum rostro paulo longius. 

 Pedes antici longiores, tenues, digito dimidio breviore quam mamts; 

 2di crassiusculi, breces, subcequi, manu oblongd, digitis manu plus 

 dimidio brevioribus, brachio ultra carapacem parce saliente. Pedes 6 

 postici breves, cequi, nudi. 



Body much depressed. Carapax naked, smooth, a little oblong, 

 broadest at middle ; beak triangular, obtuse. Inner antennae very 

 short, flagella subequal, two joints next preceding not oblong. Scale 

 of outer antennae not reaching beyond apex of beak, flagellum a 

 little longer than beak. Feet of anterior pair longest, slender, 

 finger half as long as hand ; second pair rather stout, short, sub- 

 equal, hand oblong, fingers less than half the length of hand ; arm 

 but little salient beyond carapax. Six posterior feet about equal, 

 naked. 



Plate 37, fig. la, animal, enlarged; b, under view of abdomen; 

 c, under view of anterior part of cephalothorax, more enlarged ; d, 

 one of the branchial leaflets. 



