120 PROCEEDINGS OP THE AMERICAN ACADEMY 



Of this species I have seen but one specimen, a male of the second 

 form, collected by Prof. D. S. Jordan in the Etowah River near 

 Rome, Georgia, communicated by Mr. P. R. Uhler of Baltimore. It 

 has a toothed rostrum and first abdominal appendages like G. Bar- 

 tonii. It is distinguished from the other allied species by its flat 

 rostrum and narrow areola. 



11. C. cornutus, sp. nov. 



Male, form I. Rostrum long, narrow, excavated above ; margins 

 divergent at the base, thickened, concave, costate ; acumen long, with 

 upturned horny tip ; lateral teeth at base of acumen upright, stout, blunt, 

 horny. Post-orbital ridges sulcate on the outer side, with well-devel- 

 oped horny-tipped anterior spines. Carapace flat, smooth, and punctate 

 above, granulated on the sides ; a depression on each side just outside 

 the orbital ridges ; no sub-orbital angle nor spine ; cervical groove 

 sulcated, sinuate, with a strong, sharp lateral spine ; no branchiostegal 

 spine ; areola long, of moderate width, plane, punctate, widening at 

 the posterior end of the carapace. The length of the areola is equal 

 to the distance from the cervical groove to the base of the rostrum. 

 Abdomen broad, as long as the cephalo-thorax without the acumen of 

 the rostrum, pleura triangular, with sharp lateral angles. Terminal 

 segment of telson broader than long, posterior border rounded ; ante- 

 rior segment of telson bispinous on each side. Anterior process of 

 epistoma very broad, short, triangular; apex not truncated nor notched. 

 Thoracic sterna ciliated. Basal segment of antennule with a spine on 

 lower side on the distal half of the segment. Antennas longer than 

 the body, flagellum very large, composed of annulations flattened in 

 the vertical direction, conspicuously bearded along the inner margin. 

 Antennal scale oblique to the horizontal plane of the body, a little 

 longer than the rostrum, inner margin straight and parallel with the 

 outer margin, sub-truncate at the tip, apical spine strong, long and 

 acute ; second segment of antenna with a large external spine at base 

 of the scale ; another small but well-formed external spine on the fol- 

 lowing segment below. Chelipeds large. Chela of moderate size; 

 hand smooth, punctate, internal margin serrate; fingers of moderate 

 length, curved slightly downwards, ribbed and punctate above, tips 

 incurved, horny ; external finger serrate on outer margin, impressed 

 above and below at base ; inner borders of fingers tuberculate and cili- 

 ated especially at their bases. Carpus smooth, lightly punctate above, 

 with a strong median internal spine and a small basal internal spine ; 

 a sharp, prominent median anterior spine beneath. Meros smooth, a 



