(356 MB. E. J. MIERS ON THE 



enlarged. Merus joint of outer maxillipedes notched at its an- 

 tero-internal angle. 



Subgenus 1. Leptomitheax, Miers. Anterior legs in male 

 elongated, slender ; band and wrist subcylindrical ; wrist not 

 ridged, fingers meeting along tbeir inner edges when closed. (Cara- 

 pace not spinose above.) Type Leptoinithrax longimanus, Miers. 



Subgenus 2. Paeamitheax, M.-Edio. Anterior legs in the male 

 enlarged ; band compressed, fingers witb a vacant sjoace between 

 them when closed, wrist witb two ridges, tbe outer usually oblique. 

 (Carapace usually spinose above.) Type Paramithrax Peronii, 

 M.-Edw. 



As regards external form, every gradation appears to be estab- 

 lished between the typical Paramithrax and AcantJiophrys, in which 

 the carapace and legs are more or less spinose, the upper orbital 

 margin produced above ; but the spine at the antero-external 

 angle of the basal joint of the antennge projects laterally instead of 

 forward, as in that genus ; and the form of the merus joint of 

 the outer maxillipedes is different. 



(The genus ^^Phy codes, established by A. Milne-Edwards on a 

 species, P. antennarius, from St. Vincent, has, I believe, never 

 been figured, but should perhaps be referred to the vicinity of 

 Paramithrax. The carapace is pyriform. Spines of rostrum short, 

 acute. Orbits large, ill-defined, emarginate above ; eyes par- 

 tially retractile; postocular spine large. Basal antenual joint 

 long, enlarging distally, ending in two spines, of which the outer 

 is very prominent; flagellum inserted outside rostrum. Third 

 joint of outer maxillipedes much larger on its outer than its inner 

 side. Ambulatory legs long ; dactyli curved. There appears to be 

 some inconsistency in the generic and specific descriptions of the 

 frontal and orbital region.) 



*Oplopisa, a. Ililne-Pdioards. Carapace pyriform. Spines 

 of rostrum straight, divergent. Anterior margin of buccal cavity 

 much more prominent on the sides than in the median portion. 

 Merus joint of outer maxillipedes much dilated at its antero- 

 external angle. Ambulatory legs short, and regularly spinose. 

 Type Oplopisa spinipes, A. Milne-Edwards. 



AcANTHOPUKTs, A. MiIne-PJdica7'ds. Carapace subtriangular. 

 Spines of rostrum divergent. Upper orbital margin prominent. 

 Supraocular spine produced above the eye. Basal antennal joint 



