146 AUSTRALIAN MALACOSTRACA. 



Sub- Genus Petrolisthes. 

 Sides of the rostrum entire. Lateral margins of the carapace 

 with only a single post-ocular spine, or smooth. Anterior legs 

 with the arm and hand broad, of moderate length ; arm usually 

 with teeth on the anterior margins. [iLf.] 



274. Petrolisthes elongatus. 



Porceilmia elonr/ata, M.-Edw., Hist. Nat, Crust., ii., p. 251 ; 

 White, Dieffenbach's New Zealand, ii., p. 265. 



Petrolisthes elongatus, Miers, Zool. " Erebus and Terror," 

 Crust., p. 3, pLiii., fig. 3 (1874) ; Cat. Crust. N.Z., p. GO (1876). 



Carapace slightly granular; gastric region with two slight 

 elevations, and separated from the rest of the carapace by a 

 very distinct groove; lateral borders of the carapace acute. 

 Front triangular, little deflexed, very prominent, with a deep 

 mesial furrow. Anterior legs having the posterior border of the 

 carpus armed with two or three spiniform teeth, a very obtuse 

 tooth at the base of its anterior border. \_M.-E.~] 



Said to occur on the Australian Coast ; found also in New 

 Zealand. 



275. Petrolisthes dentatus. A.M. 

 PorceUmia dentata, M.-Edw., Hist. Nat. Crust., t. ii., p. 251. 

 Front triangular, moderately prominent, with a mesial groove, 



but without well-marked lateral grooves. Anterior border of 

 the carpus armed with four to five broad flattened teeth, its 

 posterior border with a row of teeth. [M.-E.~\ 

 Port Denison. 



276. Petrolisthes inermis. A.M. 

 Petrolisthes inermis, Haswell, Proc. Linn. Soc. N.S.W., Vol.vi. 

 Carapace longer than broad, rather flat above, obscurely 



lineolate behind and at the sides. Front rather prominent, 

 triangular, with a deep longitudinal mesial furrow. Anterior 

 legs rather depressed, the carpus as long as the carapace, its 

 anterior border acute, with a low tooth near its proximal end, its 

 posterior border with two teeth, the second at the distal end, the 

 first near it. Ambulatory legs transversely lineolate, free from 

 teeth or spines. Length W in. ; breadth | in. 

 Port Denison (Mr. Alex. Morton). 



