S. I. Smith on American Crustacea. 167 



second pair in tlie female, and the tips of the others in both sexes 

 with a very short and close, clay-colored pubescence, looking much 

 like a uniform coating of mud. 



Female. The carapax is very strongly convex in all directions 

 and the dorsal surface, beneath the pubescence, is smooth and shining. 

 The cardiac region is protuberant and is separated from the gastric 

 region by a conspicuous sulcus, and from the branchial regions, by 

 very marked and deep depressions, which extend along the cervical 

 suture to the hepatic region. The branchial regions are protuberant 

 along their inner sides. The front is not protuberant, is strongly 

 detiexod, and has a slight median depression. 



The external maxillipeds are more longitudinal and of a firmer con- 

 sistency than is usual in the genus. The merus is short and broad, 

 and the inner margin is angulated in the middle, the portion toward 

 the base fitting the anterior margin of the sternum and the distal por- 

 tion being slightly concave and fitting closely the terminal segments of 

 the palpus. The second segment of the palpus is large, broadest in 

 the middle at the attachment of the terminal segment, and the outer 

 surface is flattened. The terminal segment is slightly spatulate in 

 form and reaches almost to the tip of the second segment. 



The chelipeds are equal and very stout and the hands are long and 

 nearly cylindrical. The fingers are somewhat cylindrical, nearly 

 straight almost to the tips, which are hooked by one another, and the 

 prehensile edge of the dactylus is armed, near the base, with a small 

 tooth, which fits a slight excavation in the propodal finger. 



The ambulatory legs are stout and all the ischial segments, and the 

 posterior margins of the propodi and dactyli in the last pair, are 

 clothed with a long, woolly pubescence. The dactyli in the three 

 anterior pairs are short, curved, and pubescent nearly to the tips, 

 except in the right leg of the second pair, where the propodus is con- 

 siderably longer than in the corresponding leg on the other side, and 

 the dactylus very long, almost straight, and entirely naked. In the 

 posterior legs, the dactyli are long, straight, slender, and pubescent. 



The anterior margin of the sternum is excavated into a bi'oad, 

 rounded sinus for the reception of the tips of the palpi of the exter- 

 nal maxillipeds. 



The abdomen is orbicular and completely covers the sternum. 



Male. The only male which I have seen is much smaller than the 

 females, and is not so thickly pubescent. The cardiac and branchial 

 regions are less protuberant and are separated from the gastric by a 



