MONOGRAPH OF THE LEUCOSIAD^. 285 



line aroimd the posterior margin. There is no trace of the thoracic sinus. External foot- 

 jaws extending quite to the extremity of the front, the anterior portion slightly granu- 

 lated, and the external stalk (palp) \vith the margin slightly ciuTed. The sternum in 

 each sex is bordered anteriorly Avith a line of distinct granulations. Abdomen of the male 

 with the sides parallel to witliin one-thu-d of the extremity, the remainder triangular, 

 with a strong projecting tooth. The anterior legs twice as long as the breadth of the 

 carapace ; the arm above covered with granulations for about half its length, the remainder 

 quite smooth ; -wTist rounded, perfectly smooth ; hand half as long again as it is broad, 

 slightly flattened, without any carina or granulations ; the fingers long, cui-ved, meeting 

 only at the points, and furnished mth a few distant teeth. 



Length of the carapace 0"9 in. 



Several specimens of this species from Australia exist in my own collection and in the 

 British Museum. 



Leucosia pallida, mihi (Tab. XXX. fig. 2). Fronte tridentato, ultra orbita producto ; 

 sinu thoracico in sulco brevi profundo antice terminato, granulis paucis supra inser- 

 tionem pedum anteriorum ; manibus utrinque subcarinatis omnino IjBvibus ; digitis 

 inermibus. 

 Hab. in mari orientali. Mus. Brit. 



Carapace contracted anteriorly, rounded and very convex behind ; front tridentate, pro- 

 jecting beyond the orbits; latero-anterior margin waved, granulated; hepatic region 

 slightly elevated; posterior margin projecting; thoracic sinus terminating anteriorly in a 

 deep hollow, in which are a few large granulations just above the insertion of the anterior 

 legs. Abdomen as in L. affinis. External pedipalp smooth in the male ; a slight projec- 

 tion on the middle of the inner stalk in some females. Anterior legs of moderate length ; 

 arm granulated on the upper surface, excepting an oval space on the distal tliird of its 

 length ; the under sui-face with all the middle and anterior portion smooth ; wrist small, 

 rounded, and smooth ; hand longer than it is broad, slightly carinated on each side, with- 

 out any granulations ; fingers meeting at the anterior tliird of their length, without any 

 teeth or tubercles. 



Colom- pale grey, marbled with a somewhat darker hue; four whitish spots on the 

 anterior part of the carapace, and two dark ones behind. 



Length of carapace 0-8 in. 



Several specimens of this pretty species are in the British INIuseum, obtained from 

 the Voyage of the Samarang. 



In general colour it is very different from any other ; but it has the four anterior pale 

 and the two posterior dark spots which prevail so remarkably in this genus. 



Leucoslv obscura, milii (Tab. XXX. fig. 3). Testa suborbiculari, rostro ultra orbita 

 producto, minute tridentato; sinu thoracico angustissimo ; manibus longioribus 

 quam latiorilnis, utrinque carinatis, non granulatis ; digitis inermibus. 

 Hab. ad insulas Philippinas. Muss. Brit., Bell. 



Carapace suborbicular, front tridentate, the middle tooth the longest ; margin gi-anu- 



2p2 



