PROCEEDINGS OF THE NATIONAL MUSEUM. 27 



Chelipeds in tlie feinalo uiie'|UiiI. The margins of the nierus are 

 spiuiilous, the upper margin with a sharp spiue near the carpus, the 

 inner surface tuberculous at its base, the lower surface with a trans- 

 verse tuberculous ridge at its distal end. The carpus has two strong 

 spines on its inner margin, and a row of about 7 smaller spines on 

 the anterior margin, two of which are close to the condyle of the manus 

 and are separated by a wide interval from the remaining spines. 

 Sometimes one of the spines is bifid, and occasionally additional spin- 

 ules occur on the upper surface behind the marginal spines. The 

 manus is slightly swollen, with a convex lower margin and ahnost 

 straight upper margin, wliich sometimes in the smaller chelii)ed has a 

 small sharp spine at the distal end; in a few specimens there are one 

 or two spines at the proximal end. Fingers irregularly dentate on 

 their prehensile edges and slightly gaping. The ambulatory legs are 

 rather broad, flattened; meral joints with two spines at the distal end; 

 carpal and propodal joints strongly spined above; carpal joints with 

 distal spines in the first pair and often in the second and third pairs; 

 propodal joints with a few spines below; dactyli with four rows of 

 spines. 



Measurements. — (No. 18060, female.) Length, 30.5 mm.; greatest 

 width, ;>S; width between postorbital spines, 10. 



The male is unknown. 



This species can be distinguished from other Thelphusida^ by its 

 produced, round-lobcd IVont, narrow orl)its, and numerous si)ines. 



