150 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 48. 



anteriorly, edge bilobed with a shallow emargination, outer angles 

 rounded. 



The eyes are of fair size; the stalk tapers a little distally; cornea 

 well-developed, covering the whole end of the stalk. The basal seg- 

 ment of the antennules is ventrally flattened; second segment very 

 long, as long as the orbit is wide; third segment five-sixths as long as 

 second; flagellum about one-third as long as the preceding segment, 

 each of its segments fringed with long hair, longer than the whole 

 flagellum. The epistome is much deeper in the middle than else- 

 where, curving backward between the palps of the maxillipeds; the 

 edge is thin and vertical. Sides of buccal cavity parallel. Maxillipeds 

 widely gaping, the gape wider than either endognath; outer margin of 

 merus convex. 



Chelipeds very unequal; the merus is sparingly furnished with fine 

 granules, the lower edge bears a few spines; the carpus has a strong 

 inner spine, and its upper surface is inwardly granulate; the palm has 

 rounding margins and is granulate above; fingers of the large chela 

 irregularly toothed; on the dactylus there is a large tooth near the 

 base, then a small one followed by a sinus and a medium-sized tooth; 

 opposite this cluster of teeth the immovable finger is armed with an 

 irregular molariform tooth which is directed outward; near the tip 

 are two teeth diminishing distally; the fingers gape moderately 

 except at the terminal third; lower edge of fixed finger convex. The 

 palm of the smaller chela of the male has on the inner surface reaching 

 from the middle to the lower edge a large blunt compressed tooth; 

 proximal to this tooth the surface is deeply hollowed out, the cavity 

 embracing also a part of the outer surface. When the cheliped is 

 flexed, the tooth fits in a sinus on the inner margin of the arm between 

 two tubercles. The fingers fit close together; those of the dactylus 

 are all shallow except one near the base; those of the fixed finger are 

 narrower and more acute and about four of them at intervals are 

 enlarged. 



Legs slender, pubescent, and hairy, first three dactyli styliform, 

 fourth recurved. 



Abdomen and sternum granulate; abdomen small; first segment 

 very short especially across the middle; second widening distally; 

 third, fourth, and fifth fused; outer angles of third blunt; sixth with 

 a low, broad, terminal tubercle; terminal segment suboblong. A 

 broad plate is intercalated between the fourth and fifth segments of 

 the sternum. 



This species is nearest to C. typicus 1 7 in which the carapace is nar- 

 rower, the chelae flattened, the fingers of the larger chela strongly 

 deflexed and evenly toothed. 



i Rathbun, Bull. Labor. Nat. Hist. State Univ. Iowa, vol. 4, 1898, p. 285, pi. 7, figs. 3-6. 



