OP ARTS AND SCIENCES. 133 



Walter Faxon, and Cat. No. 3575 (male, form IL), from Bradford, 

 Ind., A. S. Packard, Jr., probably belong to this species, but the speci- 

 mens are too young to determine with confidence. 



This species resembles G. spinosus, from which it is easily distin- 

 guished by the length of the posterior section of the carapace, and by 

 the length of the male appendages. From C. affinis it may be sepa- 

 rated by the different form of the male appendages and female annu- 

 lus ventralis, and by the single lateral spine of the carapace. I have 

 seen males of the first form only 34 mm. in length. 



20. C. FORCEPS, sp. nov. 

 Male, form I. Rostrum narrow, excavated, faintly carinated in the 

 middle ; margins divergent at the base, thickened, dotted-lined ; acumen 

 long and narrow, horny tipped; lateral spines small. Post-orbital 

 ridges not very prominent except anteriorly, where they terminate in 

 a spine with a corneous tip. Carapace cylindroidal, punctate above, 

 granulated on the sides, antero-lateral margins bluntly angulated; 

 cervical groove sinuate ; small and acute lateral spine : no branchios- 

 tegian spine ; areola of moderate width, punctate. Abdomen as long 

 as the cephalo-thorax : telson rounded behind, bispinose on each side. 

 Epistoma smooth, anterior process triangular, in some specimens trun- 

 cate. 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, sub-truncate at distal end, outer margin ending in a 

 long, sharp, somewhat outwardly directed spine. Third pair of maxil- 

 lipeds hairy within. Chelipeds short, stout; chelte large, wide, with 

 slender cylindrical, widely-gaping fingers, wdiich 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, a strong, sharp internal median spine ; below there is no ante- 

 rior median spine, and only a very minute external one. IMeros 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 tlie 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 



