BY WILLIAM A. IIASWELL, M.A., B.SC. 251 



pereion ; flagellum and peduncle subequal. Anterior gnathopoda 

 of moderate size, the carpus with a projecting ciliated process on 

 its inferior border ; the propodos ovoid ; palm oblique, convex, 

 denned by a blunt tooth. Posterior gnathopoda large ; the 

 propodos more than twice as long as that of the anterior pair, 

 ovoid, its proximal border with a deep notch, its superior border 

 strongly convex, palm scarcely oblique, convex, armed with an 

 obscure tooth. Pereiopoda of the two anterior pairs subequal. 

 Three posterior pairs of pereiopoda increasing progressively in 

 length from before backwards. Posterior pleopoda short. Telson 

 nearly semicircular, divided. 



Length four-and-a-half lines. 



Sab. Shallow rock-pools a little above high-water mark, Clark 

 Island, Port Jackson; Botany Bay. 



This species is distinguished from A. Gaimardii ( ' Ampliitlioe 

 Gaimarditj Edwards, Hist, des Crust, iii. 37 ; Allorchestes compressa, 



Dana, Proc. Amer. Acad. Set'. Bost. ii. 205 ; Allorchestes Gaimardii, 

 U. S. Explor. Exped. p. 181, pi. 60, fg. 1 ; Spence Bate, Cat. 



Amph. p. 41, pi. Q,fig. y.y which seems to be its nearest ally, 



chiefly by the form of the anterior gnathopoda. 



Allorchestes longicornis, sp. nov. (PL VII., fig. 4.) 



Inferior antennae as long as the cephalon and the whole of the 

 pereion ; third segment of peduncle short ; fifth the longest ; 

 flagellum more than twice as long as the peduncle. Superior 

 antenna) with the peduncle as long as the third and fourth segments 

 of the peduncle of the inferior pair ; first and second joints sub- 

 equal ; third smaller ; flagellum twice as long as the peduncle. 

 Anterior gnathopoda with the carpus sub -triangular, having a 

 small hairy process on its ventral aspect ; the propodos equal in 

 length to the carpus, rather longer than broad, its dorsal border 

 nearly straight, its palmar border strongly convex ; palm oblique, 

 defined by a small tooth. Posterior gnathopoda with the propodos 

 twice as long as that of the anterior \ air, heart-shaped, nearly 



