120 A REVISION OF THE ASTACUXE. 



and narrow, horny-tipped ; lateral spines small. Post-orbital ridges not very 

 prominent except anteriorly, where they terminate in a spine with a corne- 

 ous tip. Carapace cylindroidal, punctate above, granulated on the sides, 

 antero-lateral margins bluntly angulated; cervical groove sinuate; small and 

 acute lateral spine ; no branchiostegian spine ; areola, of moderate width, 

 punctate. Abdomen as long as the cephalothorax ; telson rounded behind, 

 bispinose on each side. Epistoma smooth, anterior process triangular, in 

 some specimens truncate. Thoracic sterna with silky seta? at bases of the 

 legs. Antennae slender, as long as the body ; scale a little longer than the 

 rostrum, of moderate width, subtruncate at distal end, outer margin ending 

 in a long, sharp, somewhat outwardly directed spine. Third pair of maxilli- 

 peds hairy within. Chelipeds short, stout; chela? large, wide, with slender 

 cylindrical, widely gaping fingers, which are curved outward at the base and 

 opposable only at their tips; hand thickly punctated above and below, inner 

 margin obscurely serrate ; fingers naked at base, with parallel rows of ciliated 

 dots ; a dark band around both the inner and outer fingers a little distance 

 from the tip. Carpus punctate above, with a strong, sharp internal median 

 spine ; below there is no anterior median spine, and only a vei'y minute ex- 

 ternal one. Meros short; of the biserial inferior spines only the distal one 

 in each row is usually developed to any extent ; above there are commonly 

 two obliquely placed ante-apical spines, in some specimens only one. Distal 

 portion of the following pairs of legs furnished with long seta?, especially 

 long on the second pair of legs. Third segment of third pair of legs hooked. 

 First pair of abdominal appendages long, deeply bifid ; rami slender, straight, 

 parallel, the outer a little longer than the inner, and a little recurved at the 

 tip ; in some specimens the anterior border at the base of the rami has a 

 projecting angle or shoulder, but in most specimens this is not evident. 



Female. — Fingers straighter. Base of external finger has a dense beard 

 on the inside; in a few of the specimens seen, the fingers are longer, nearly 

 straight, their opposed margins almost meeting throughout their length. 

 Annulus ventralis bilaterally symmetrical, anterior margin bituberculate, 

 posterior margin unituberculate, fossa transverse. 



Dimensions of a nude, form I. — Length of body, 38 mm. Length 

 of carapace, L9.5 mm. Length of abdomen, 18.5 mm. From tip of ros- 

 trum to cervical groove, 14 mm. From cervical groove to posterior bor- 

 der of carapace, 6 mm. Length of rostrum, 5 mm. Length of acumen of 

 rostrum, - mm. Width of areola, 1 mm. Length of antenna. .'Hi mm. 



