92 AUSTRALIAN HALACOSTItACA. 



Genus Gelasimus, Latr. 



Eyes slender, cornea rather small, scarcely oblong. Second 

 joint of the external maxillipedea much larger than the third. 

 Anterior legs of the male extremely unequal. Smaller hand 

 weak, with the fingers usually spoon-excavate or spatulate. 



159. Gelasimus vocans. 



Cancer vocans, Rumph., Amboin. Karcit. Kam., pi. x., fig. E 

 (1705) ; Linne, Syst. Nat., 10th ed., 626. 



Gelasimus vocans, M.-Edw., Melanges Carcinologiques, p. 109, 

 pi. iii., fig. 5 ; Annales des Sci. Nat., t. xviii., p. 145 ; A. M.-Edw., 

 Nouv. Arch, du Mus., ix., p. 272 ; Miers, Ann. and Mag. Nat. 

 Hist. (5), Vol. v., p. 80S (1880). 



Front very narrow and little enlarged below. A strong 

 triangular tooth near the distal end of the upper margin of the 

 arm. Large hand granular externally, armed internally with 

 two very strong, oblique crenulated crests ; fingers much com- 

 pressed, the trenchant border of the mobile finger regularly 

 toothed that of the immobile finger is excavated near its base, 

 and has always a strong triangular lobe or tooth near its distal 

 extremity, with sometimes a second between this and the base. 



AVoodlark Islands, Louisiade Archipelago ; Port Darwin. 



160. Gelasimus arcuatus. 



Ocypode (Gelasimus) arcuatus, De Haan, Faun. Jap., Crust., 

 p. 53, pi. vii., fig. 2 (1835). 



Gelasimus arcuatus, Milne-Edwards, Ann. des Sci. Nat., 3me. 

 serie, t. xviii., p. 11G, pi. iii., fig. 8; A. M.-Edw., Nouv. Arch, du 

 Mus., t. ix., p. 273; Miers, Ann. and Mag. Nat. Hist. (5), Vol. v., 

 p. 309 (1880). 



Carapace very narrow behind and convex above. Front 

 narrower between the eyes, dilated below. Large hand much 

 developed, the hand becoming very long, but gradually narrowing 

 towards the end; mobile linger hooked at the extremity; 

 immobile finger with a pretty strong iooth about the middle of 

 its length; sometimes without prominent lobes ; sometimes three 

 times the length of the hand. 



Port Darwin. 



