4 PEOCEEDIN-GS OF THE NATIONAL MUSEUM vol. 73 



The under side of the carapace (pi. 2, fig. 4) is more coarsely 

 granulate than the upper, the granules more distant ; on the margins 

 and along the pterygostomian ridge the granulation is fine and 

 close. The remains of the buccal cavity and the outer maxillipeds 

 indicate the following: The buccal cavity widens forward, its an- 

 terior margin sinuous. The exognath and endognath of the maxil- 

 lipeds are wide, the exognath widest at the middle; endognath 

 obliquely placed, ischium widening distally, merus obliquely placed, 

 its anterior margin fitting against the arch of the buccal margin. 

 On the sternum at the base of the cheliped and either side of the 

 proximal end of the terminal segment of the female abdomen 

 there is a large tubercle obliquely compressed. The first five seg- 

 ments of the mature abdomen are short, the sixth is nearly twice as 

 long as the fifth, measured at the middle, and is longer at the sides, 

 the distal margin being a broken line; terminal segment not quite 

 so long. Surface coarsely and unevenly punctate. Length of cara- 

 pace approximately (front margin broken off) 35 millimeters; width 

 to base of lateral tooth, 44.6; fronto-orbital width, 23 millimeters. 

 Oat. No. 369607, U.S.N.M. 



A pair of loose chelae, one with fingers (pi. 2, figs. 1 and 2), may 

 belong to the holotype as they have the same rusty coloration and 

 gloss. Left palm about two-thirds as high as right. A large tuber- 

 cle opposite the digital sinus and an oblique line of three tubercles 

 on the proximal half; the upper and middle tubercles are elongate 

 and similar, the middle one shorter ; the lowest one is conical ; a lobe 

 on inferior margin at proximal end. Upper margin incomplete in 

 both palms but having three large tubercles, while the hinder portion 

 in the smaller palm is produced in a lamina bearing three smaller 

 tubercles (fig. 2, 3t). An outer margin of the upper surface shows a 

 few low swellings. The inner surface (pi. 2, fig. 2) has through the 

 middle a short longitudinal line of granules, three on the larger 

 palm, four on the smaller. Fingers of the larger chela similar, short, 

 triangular in side view; prehensile edge largely occupied by two 

 huge, low molariform teejth or tubercles. 



Paratype a: One concretion yielded not only the body of a crab 

 but a manus. The front between the eyes is fairly well shown 

 (pi. 2, fig. 6) ; the median teeth are separated by a very shallow 

 sinus and are only slightly in advance of the lateral pair. 



Paratype h (pi. 2, fig. 5) shows the position of the outer maxillipeds 

 and the basal antennal article {a). 



Males. — Paratype c: The male (pi. 3, figs. 1 and 2) which was 

 found outside a concretion is much larger than any of the females; 

 carapace about 72 millimeters wide, but so damaged that few charac- 

 ters are discernible. One lateral tooth (perhaps the third) remains 

 (pi. 3, fig. 2^) ; it is strong, conical, obliquely upturned ; the inter- 



