AUSTRALIAN MALACOSTEACA. 145 



Greatest breadth of carapace considerably greater than half 

 the length. An acute spine directed forwards situated at the 

 junction of the antero-lateral and postero-lateral borders. Front 

 trilobate, the mesial lobe broad at the base, triangular, acute, the 

 lateral lobes narrower, acute. Surface of carapace minutely and 

 closely punctate. Carpus of chelipedes armed with two acute 

 spines above ; hand compressed, carinate above, the carina 

 ending anteriorly in a small spinule ; the lower border with 

 three acute spines ; immobile finger perpendicular to the direc- 

 tion of the axis of the hand; extremities of fingers hooked, 

 acute. 



A specimen of this species was obtained with the dredge at 

 Port Stephens, and another is in the collection of the Hon. 

 William Macleay, and was dredged outside the "heads" of 

 Port Jackson. It was originally found on the Coast of Japan. 

 The Australian specimens agree closely with De Haan's figure, 

 and that obtained recently by Capt. St. John in the Japanese 

 Seas, and described by Miers (P.Z.S., 1879, p. 46), belongs cer- 

 tainly, as the latter conjectures, to a distinct species. 



Section ANOMOURA MEDIA. 



Eyes not anterior to the antennules. Antennae behind and 

 external to the eyes. Abdomen inflexed but not closely appressed, 

 provided with caudal appendages. Mouth never as in the 

 Leucosiidce. 



Sub-Tribe Porcellanidea. 



Carapace sub-orbiculate. External maxillipedes scarcely oper- 

 culiform, the third joint little smaller than the second. Second, 

 third, and fourth legs gressorial, fifth weak, inflexed. 



Genus Petrolisthes, Stimpson. 



Carapace depressed, sub-ovate, not broader than long, the 

 front triangular, prominent, margin more or less undulated, 

 toothed or entire. Eyes rather large. Antennae with the 

 peduncle more or less cristate, the first joint of the external 

 antennae short, not reaching the margin of the carapace. Hands 

 broad, depressed. Tarsi of the ambulatory legs short, rather 

 robust, with a single claw, [ilf.] 



