REPORT OX THE BRACHYURA. z -- 



CORYSTIDA 



Hypopeltarium dextrum sp. nov. PL vi. Fig. 2. 



Carapace oval: median tooth of front longer than the lateral ; 

 chelipeds very unequal: seven abdominal segments in the male 

 distinct. 



This species resembles H. spinulosum in the shape of the 

 carapace and lateral lobes, the character of the rostrum, orbits, 

 antennae and maxillipeds. It differs from it in its very unequal 

 chelipeds and in the separation of the seven abdominal seg- 

 ments. In these points it resembles Trichopeltarion. 



Carapace narrow, oval, broader anteriorly than posteriorlv. 

 very convex, strongly deflexed anteriorly. Surface orna- 

 mented with numerous small, white, bead-like tubercles which 

 posteriorly become subacute or spiniform. The surface be- 

 tween the tubercles is covered with very short light-colored 

 setae. Branchio-cardiac sutures very deep. Front horizontal, 

 tridentate, median tooth twice as long as the lateral, each 

 tooth tipped with a sharp spine, and with two or more smaller 

 spines near the tip. Orbit four-toothed as in H. spinulosum. 

 the teeth margined with small spines. Eve-stalks slender, 

 curved, capable of being concealed within the orbits. Eves 

 imperfectly developed, light brown. About one-third the dis- 

 tance from the tip on the anterior surface there is a small 

 slender spine. 



On the lateral margins of the carapace, three shallow teeth 

 or lobes can be made out. two of which are antero-lateral and 

 one postero-lateral: they are bordered by small spines. In- 

 ferior surface of the carapace spinulous. The sutures between 

 the abdominal segments are distinct. The terminal segment 

 is not deeply inserted in the preceding segment as in H. spinu- 

 losum. and is considerablv broader than long. The median 

 third of the abdomen is spinulous. the spinules diminishing 

 in size from the first to the sixth segment. Sternum granulate. 

 Antenna with basal joint stout, spinulous, partially movable. 

 and attaining the end of the subocular tooth, second and 

 third joints successively much more slender. The maxillipeds 



