's RIJKS MUSEUM VAN NATUURLIJKE HISTORIE — LEIDEN. 173 



meropodites is spiny ; there is only one white-tipped larger tooth, followed 

 by a few much smaller ones, that are more properly to be called sharp 

 granules rather than teeth, in the interspace between the large tooth and 

 the articulation with the carpopodite ; in the case of the last pair of legs, 

 there are moreover one or two teeth at the under hind margin of the 

 meropodite, near the basal end. These characters of the legs agree almost 

 wholly with those of P. granulosus. 

 Dimensions : 



Length of carapace 16.5 mm. 



Maximum breadth of carapace 18.5 „ 



Breadth of anterior margin of front ....... 7. — „ 



Breadth of posterior margin of carapace 7. — „ 



Horizontal length of palm and immobile finger . . . 13.5 „ 



Height of palm 8.5 „ 



Length of penultimate pair of legs 21.5 „ 



Posterior margin of penultimate segment J [ 4.25 „ 



Anterior margin of penultimate segment I of male j 2.25 „ 

 Length of penultimate segment j abdomen 2. — „ 



Length of terminal segment ] [ 2.25 „ 



The single specimen, a male, was found at Mas, near the west coast 

 of Sumatra, by Dr. Kleiweg de Zwaan. Whether it occurred in fresh or 

 brackish waters is not known. 



3. Pyxidognathus detanira de Man (PI. XI, Fig. 3). 

 De Man (1. c.) has given a minute description of this species, but his 

 only adult specimen was a female. The concise account of Alcock (Journ. 

 As. Soc. Bengal, v. 69, prt 2, 1900, p. 407) was based on the two young 

 males mentioned by de Man. I have examined an adult male, and it may 

 be of some use to indicate shortly its characters. In giving a full des- 

 cription I should have to repeat chiefly de Man's statements. 



The present species is distinguished from the two preceding ones by 

 the following features: 



1° The carapace has nearly parallel side-margins; the two epibranchial 

 teeth, behind the external orbital angle, are spiniform, prominent, and 

 the incisions separating the three teeth of either side are deep and 

 sharply cut; the external orbital angle is as large as the two other 

 teeth together, its lateral margins are diverging backward ; the posterior 

 tooth is smaller than the preceding one. The granulation forming the 

 outline of the carapace is much finer than in the two preceding species. 

 2° The carapace is much less vaulted especially in transverse direction, 

 and is nearly entirely smooth, with scarcely any indications of the 



