MONOGRAPH OF THE LEUCOSIAD^. 287 



Carapace somewhat rhomboid, rounded at the posterior margin ; the front projecting 

 beyond the orbits, slightly emarginate ; hepatic region with a slight central elevation ; 

 thoracic sinus terminating anteriorly in a notch bordered with large granulations ; lateral 

 margin strongly granulated. External foot-jaws flat, smooth, with the outer margin 

 straight. Anterior margin of the sternum granulated. Anterior pair of legs nearly twice 

 as long as the postfrontal portion of the carapace; the arm long, with three series of 

 larger granulations on the upper side, extending to about two-thirds of its length, the 

 remaining portion entirely covered with smaller ones; the wrist somewhat triangular, 

 longer than it is broad, slightly granulated above and at the sides ; hand somewhat tumid 

 in the centre, slightly carinated on each side, the inner only granulated ; fingers touching 

 only at the point, with a large interval at the base. Abdomen (male) broadest at the 

 base, where it is furnished with two large oval protuberances ; the penultimate segment 

 oval, with its posterior margin truncate. 



Length of carapace 0*8 in. 



Colour greyish-brown, with two darker spots on the branchial regions. 



This species, of which a single specimen exists in the British Museum, differs from all 

 others that I am acquainted with in the very distinct punctuation of the whole surface of 

 the carapace. The arm also is covered with minute granulations at the anterior portion, 

 which in most species is quite smooth. In other respects it very much resembles the 

 following species, L. affinis. Its habitat is not absolutely known, but it is in all proba- 

 bility from the Indian Ocean. 



Leucosia affinis, mihi (Tab. XXX. fig. 6). Testa antice angustata, fronte valde pro- 

 ducto, subemarginato ; manibus longioribus quam latioribus, utrinque carinatis; 

 brachiis antice tumidis, lsevissimis, politis. 



Hab. ad insulas Philippinas. <J Mus. Bell. 



Carapace somewhat rhomboid, narrowed anteriorly, with a few scattered punctures ; the 

 front much produced, with a triangular elevation extending backwards, and a depression 

 on each side of the front, the extremity slightly emarginate, and extending beyond the 

 orbits. The thoracic sinus short, extending backwards but little beyond the insertion of 

 the anterior legs, terminating in front in a granulated notch. Anterior legs rather long, 

 the arm above with about three series of granulations, which are larger at the base, 

 becoming smaller forwards, the distal portion tumid, polished and free from granulations, 

 excepting at the inner margin ; the wrist rounded, with a single row of small regular 

 granulations on the inner side ; hand longer than broad, carinated on each side, the inner 

 with a granulated area, bordered with large granulations ; fingers meeting only at the 

 point. Poot-jaws and abdomen as in L. punctata. 



Length of carapace 07 in. 



This species greatly resembles the former in most of its characters ; it is however easily 

 distinguished by the almost total absence of punctures on the carapace, and especially by 

 the naked polished area on the distal portion of the arm. 



A single specimen (male) is in my collection, received from Mr. Cuming. 



