20 AUSTRALIAN MALACOSTKACA. 



so long as the first pair of ambulatory legs, which are longer 

 than any of the succeeding. 



This genus ought probably to be united with Xaxia. 



31. Hyastenus diacanthus. A.M. 

 Pisa (Xaxia) diacantlta, De Haan, Crust. Jap., p. 86, pi. xxiv., 



fig. 1 (1839). 



Hyastenus diacanthus, A. Milne-Edwards, Xouv. Arch, du 

 Mus., t. viii., p. 250; Miers, Cat. Crust, N.Z., p. 9 (1876). 



Hyastenus verreauxii, A. Milne-Edwards, 1. c., p. 250. 



Carapace triangular, rather convex. Rostral spines long and 

 slightly divergent. Gastric region very convex, in young 

 specimens almost tuberculated. Antero-lateral margins long, 

 straight, unarmed, terminating posteriorly in a strong spine, 

 directed outward and placed on a level with the back of the 

 branchial regions, Anterior legs in the male strong; hand 

 rather compressed. "Whole surface covered with stiff, curled 

 hairs. [il] 



Port Jackson ; Port Denison ; Torres Straits. Pound also in 

 New Zealand, the Philippines, and Japan. 



32. Hyastenus oryx. A.M. 



Hyastenus oryx, A. Milne-Edwards, Xouv. Arch, du Mus., 

 1. viii., p. 250, pi. xiv., fig. 1. 



Carapace little dilated, slightly pyriform and swollen above. 

 Rostrum formed of two long, slender, pointed, divergent cornua. 

 Orbit large with a wide fissure above. Gastric region convex, 

 ornamented with three tubercles in the middle line, and two 

 pairs behind with four less distinct on each side. Cardiac and 

 branchial regions with numerous tubercles. Surface yellow, 

 marked with spots of brighj red, covered with very short, 

 scattered brownish hairs. [A. M.-E.~\ 



Torres Straits; Port Denison. Found also in New Caledonia. 



Genus Naxia, Milne-Edwards. 

 Hardly to be regarded as a distinct genus from the preceding. 



