aS. I. Smith on American Crustacea. 117 



and densely verrucose externally, the superior and inferior margins 

 are thin and dentate, and the inner surface is nearly smooth, excepting 

 three, high, tuberculose crests, of which one runs obliquely upward 

 from tlie inferior margin, one from the base of the dactylus along the 

 margin of the depression into which the carpus folds, meeting the 

 first in nearly a right angle, and another along the margin next the 

 base of the dactylus, leaving a rectangular, depressed area between it 

 and the lower crest. Both the fingers are smooth on the inside, quite 

 long, compressed and high, and the prehensile edges are evenly tuber- 

 culated and each armed with a single, stout, median tooth. The oute r 

 sui-fiTce of the propodal finger is somewhat roughened with irregular, 

 shallow punctures, the inferior edge is granulated and has a submar- 

 ginal, granulous line on the outer side, and the prehensile edge is armed 

 with a stout tooth considerably within the tooth on the dactylus ; 

 the edge beyond this tooth is straight and closes evenly against the 

 dactylus, but between the tooth and the base it is deeply excavated, 

 leaving a short and broad opening between the bases of the fingers. 

 The dactylus is smooth on the outside, except a small space at the 

 base, its superior edge is entire and smooth, and the prehensile edge 

 is nearly straight, tuberculated and armed with a stout tooth a little 

 beyond the middle. 



In the smaller cheliped the merus is slender and somewhat trique- 

 tral, and the superior and exterior angles are sharp. The carpus is 

 short, ovoid in form, and smooth and rounded externally. The hand 

 is slender, and the fingers long, flattened at the tips, and the angles 

 clothed with hairs. 



The ambulatory legs are smooth and unarmed. 



The abdomen is contracted at the articulation of the first with the 

 second segment, and the edges are straight from the second segment 

 to the terminal, which is broad and obtusely rounded at the extremity. 



Four specimens gave the following measurements : — 



1. 2. 3. 4. 



Length of carapax, 18-7mm iS-Sm™ 18-2mm le-gmm 



Breadth of " 



Ratio of length to breadth, . - . - ] 



Length of larger hand, 



Length of ocular peduncle on side of smaller cheliped, 140 

 Length of ocular peduncle on side of larger cheliped, 



excluding stylet, 



Length of terminal stylet of ocular peduncle, 



In numbers 3 and 4 the ocular stylets are broken and partly wanting. 

 Quite a number of specimens are in the collection of the Peabody 



