STALK-EYED CRUSTACEA 43 



extremity is truncated. The first and second pairs of 

 legs are long". 



Range. — St. Thomas, 



3. Acanthonyx. 



AcantJionyx . . . Latreille, H. Milne Edwards, 



Miers. 

 Maia Risso. 



Carapace suboblong, rounded behind, and with the 

 dorsal surface depressed, not markedly constricted behind 

 the prominent antero-lateral angle ; the lateral branchial 

 spine small. Prseocular spines prominent, acute. The 

 rostrum is horizontal, triangular, with its extremity 

 notched. Eyes small, mobile. The orbits are circular. 

 Basal joint of external antennae narrowing slightly from 

 base to dilated extremity, which is unarmed ; flagellum 

 visible on a dorsal view at each side of the rostrum. 

 The fourth joint of the external maxillipedes is truncated 

 distally, and slightly notched at its antero - internal 

 angle. 



The first pair of legs, in the male, is well developed ; 

 palm compressed, but slightly turgid in the middle, and 

 often slightly keeled above ; fingers acute, but having 

 between them, when closed, an interspace at the base. 

 Walking legs short, with the last joint but one 

 flattened, dilated, and notched on its inferior margin, 

 against which the curved last joint, closing, forms a 

 hook. 



Abdomen in the male six-jointed. Of small size. 



Range. — Atlantic and Pacific Oceans ; in shallow 

 water. 



