166 BULLETIN OF THE 



the only male specimen obtained), coxa tuberculate on the lower face, the fol- 

 lowing segments armed with strong spines, fingers excavated within, slightly- 

 gaping, penicillate, cutting edges entire. Ambulatory appendages very long, 

 second and third pairs of about equal length and longer than the first pair; 

 all of them armed, like the chelipeds, with spines; the spines tend toward a 

 regular arrangement in longitudinal rows, and the spaces between the spines 

 are smooth and naked, i. e. nearly free from spinules, tubercles, or seta?. 

 Second segment of abdomen composed of a single calcified plate, marked by 

 a deep hollow on each side of the middle ; the other segments of the abdomen 

 are of a leathery, semi-membranaceous consistency, and are made up of five 

 longitudinal rows of plates, viz. one median row, flanked by a row on each 

 side, the latter in turn bounded externally by a marginal series ; whole sur- 

 face of abdomen verrucose. 



Length of carapace, including rostrum, 84 mm.; breadth, 78 mm.; breadth 

 between the antero-lateral angles of carapace, 34 mm. ; length of last ambula- 

 tory appendages, 242 mm. ; merus, 76 mm. ; carpus, 36 mm. ; propodus, 64 mm. ; 

 dactylus, 47 mm. 



In the female the right chela is larger than the left, and the prehensile edges 



of the fingers are furnished with blunt teeth. The abdomen is asymmetrical, 



Jrto + 'ip right, the marginal plates absent from the left side; the 



ppendage (the first). The abdomen nearly 



bi • - of the thor 1 '- u in the male are almost 



Stan, l male, 1 female o 



The egg measures 2 



Lithodes panamensis, sp. hov. 



Carapace subpyriform, of about equal length and breadth; gastric and 

 branchial regions very convex ; a deep depression on each side at the anterior 

 limit of the branchial areas, and another between the gastric and cardiac areas. 

 Rostrum cylindrical, terminating in three spines or teeth, one of which is me- 

 dian, the other two lateral; a long horn, slightly upcurved, is given off from 

 the lower side of the proximal end of the rostrum. The whole surface of the 

 carapace is rough with low warty protuberances ; the gastric region bears two 

 pairs of spines, the anterior pair separated by a greater interval than the pos- 

 terior pair. Two small spines on each branchial area, and two on the intes- 

 tinal region. The orbit is bounded externally by a prominent spine, and 

 there are five more spines on the lateral border of the carapace, viz. one at the 

 antero-lateral angle, one on the hepatic region, and three on the branchial. 

 Besides these there is a rudimentary lateral spine near the anterior limit of the 

 branchial region. The posterior margin of the carapace is tuberculated, not 

 spinose. The third segment of the antennular peduncle is equal to the first 

 segment in length, and considerably longer than the second segment. The 



