110 PROCEEDINGS OF THE AMERICAN ACADEMY 



Fingers a3 long as the hand, densely ciliated. Carpus tuberculate, a 

 prominent spine within, and one near each point of articulation with 

 the chela. Meros smooth outside and inside, tuberculate and spi- 

 nous above, biserially spinous and ciliate beneath. Third and fourth 

 pairs of legs toothed on the third segment. Fifth pair of legs with 

 a hook on the basal segment. Anterior abdominal appendages of 

 moderate length, articulated at the base, internal part with an articu- 

 lated spine obliquely placed, external part terminating in a rounded 

 head with two short, blunt teeth. 



Female. Differs from the male in its shorter and smaller claws. 

 The sternum is densely ciliated as in the male. The annulus ventralis 

 conical with sigmoid longitudinal fissure; movable. 



Length, 54 mm. Carapace, 26 mm. Abdomen, 29 mm. Distance 

 from tip of rostrum to cervical groove, 19 mm ; from cervical groove to 

 posterior border of carapace, 7 mm. Width of areola, 3 mm. Length 

 of chela, 15.5 mm. ; breadth, 4 ram. (In the female, which is 59 mm. 

 long, the chela is 12 mm. long by 4 mm. wide.) 



Two specimens, one male of the second form and one female, in 

 the U. S. National Museum (No. 3181), collected by A. Graves in 

 McBean Creek, a tributary of the Savannah River a little south of 

 Augusta, Georgia, are the types of this species. There are two young 

 female specimens from the same region, Richmond Co., in the Mu- 

 seum of Comparative Zoology. 



Differs from C. Lecontei and C. angustatus by its broader areola, 

 subplane rostrum, and the pubescence of rostrum and cervical groove. 

 The male appendages also differ, as shown in the description. 



b. Rostrum without ante-apical lateral spines (at least in full-grown specimens). 



3. C. Alleni, sp. nov. 



Male, form I. Rostrum broad, triangular, somewhat deflexed, 

 smooth, excavated above, margins raised into sharp crests and gradu- 

 ally converging to near the tip, where they suddenly approximate each 

 other to form the short, sharp acumen ; no lateral spines. Post-orbital 

 ridges without spines. Carapace cylindrical, somewhat compre?sed 

 laterally, fore border angulated behind the antenna?, punctate above, 

 gianuhited on the sides. Cervical groove deeply sulcated, without 

 lateral spines. Cardiac region more tlian one third as long as the 

 distance from the tip of rostrum to hind border of carapace. Areola 

 narrow. Abdomen broad, longer than cephalo-thorax. Angles of 

 pleura rounded. Three or four spines on each side of posterior border 



