AUSTRALIAN MALACOSTBACA. 113 



G-enus Pinnixa, "White. 



Body very obese, much broader than long ; surface perfectly 

 smooth. Front not united with the epistome. Fossae of the 

 internal antennas often coalescent. Eyes very small, placed near 

 to one another. Second joints of the external maxillipedes 

 small or obsolete. 



207. Pinnixa faba. 



Pinnothera faba, Dana, U.S. Explor. Exped., Crust., i., p. 381, 

 pi. xxiv., fig. 4. 



Carapace and outer maxillipedes naked ; outer maxillipedes 

 almost longitudinal. Anterior feet of female short, hand rounded 

 above, fingers minutely pubescent. Posterior feet quite short 

 and stout, third joint of fourth pair one- third as long as breadth 

 of carapace, tarsus short, sub-conical from a stout base, 

 uncinate at apex. [Dana.] 



A specimen found in Haliotis coco-radiata, at Port Denison, 

 differs from thali described and figured by Dana only in having 

 the legs completely smooth. 



G-enus Xanthasia, "White. 



Distinguished from Pinnotheres by having the carapace sur- 

 rounded by a narrow elevated border. 



208. Xanthasia murigera. 



• Xanthasia murigera, "White, Ann. and Mag. Nat. Hist., Vol. 

 xviii., p. 177, pi. ii., fig. 3 (1846) ; Dana, Op. cit., i., p. 384, 

 pi. xxiv., fig. G ; A. M.-Edw., Nouv. Arch, du Mus., t. ix., p. 321. 



Carapace parchment-like, surrounded by a thin, raised and 

 prominent border, which is much higher at the sides than in 

 front ; upper surface of the carapace, internal to this, excavated, 

 except in the middle where there is a much developed circular 

 and slightly pedunculated projection ; gastric region with a few 

 rugosities. Front deflexed and rounded, Eyes small and 

 immobile. Legs short and terminated by a very sharp hooked 

 nail. 



Cape Grenville (Macleay Museum). This curious species 

 inhabits the shell of species of Tridacna. 



