THE CANCROID CRABS OF AMERICA 201 



photographs of the same were sent to the U. wS. National Museum 

 through the kindness of Doctor Luederwaldt. 



Measurements. — Length of carapace 15 cm., width of same 25 cm. 

 (Luederwaldt.) Length of propodus of right cheliped 165.4 mm. 



i^ia^nos is. —First antero-lateral (orbital) tooth as wide as any of 

 the next five teeth. Basal antennal article more than twice as long^ 

 as wide. Black color of fingers covering all but a small basal portion. 

 Chelipeds narrow, merus not widening distally. 



Description. — Carapace larger than any specimen of the genus yet 

 obtained. Surface densely and coarsely granulate, not very uneven; 

 a depression behind the front. Antero-lateral border strongly arched, 

 cut into 9 broad subtruncate teeth which are defined by deep closed 

 sinuses and show each a shallow thick marginal lobule which increases 

 in prominence successively from the first to the ninth tooth. Postero- 

 lateral border with two emarginations, the first well marked, the second 

 slight. The frontal teeth between the antennae are in the same hori- 

 zontal plane, thick, subequal, tips subacute. According to the dorsal 

 view, shown in plate 86, the front is less advanced than the hepatic 

 regions but this maA^ be apparent rather than actual as the carapace 

 is much foreshortened owing doubtless to the front half being up- 

 turned; the ventral view (pi. 87) may show more nearly the real 

 relation of the front to the antero-lateral border. Inner orbital tooth 

 triangular, broad; no supraorbital tooth but the two fissures strongly 

 marked; no projecting tooth at outer angle of orbit. Basal article of 

 antenna (pi. 87) elongate, having a strong terminal tooth; a small tooth 

 close to it on the orbital margin. Epistome advanced at outer ends in 

 a large rounded lobe. Chelipeds rather narrow; merus not enlarging 

 toward distal end. Black color of fingers covering all but the basal 

 end. 



Relation. — This species is the first of the genus to be reported from 

 the Atlantic coast of South America. It is allied to C. porteri and C. 

 plehejus from the Pacific coast, has similar truncate lateral teeth, 

 although without denticulate edges; it lacks a well formed outer orbital 

 tooth present in those species; the antero-lateral margin is morfr 

 strongly arched, the basal antennal article much longer, the fingers 

 blacker. C. luederwaldti resembles C. porteri in its coarse granulation, 

 in the shape of the front, and in the long first antero-lateral tooth, but 

 differs most strikingly in the branchial regions not approximating the 

 median line. Our species approaches C. plehejus in the moderate 

 size of the chelipeds and in the flatness of the epistome, an indication 

 that it was covered by the maxillipeds (which are lacking in this case),, 

 but differs in the partial separation of the lateral teeth. 



