THE SPIDER CRABS OF AMERICA 103 



of epistome in place of two or tlirec tubercles. Sternum covered with 

 large tubercles. Sternum extended over bases of legs, forming crenate 

 border around posterior portion of carapace. Chelipeds about one 

 and a half times the length of the carapace, granulate; margins of 

 merus with short triangular spines; palms swollen; fingers very slender 

 and gaping, a large triangular tooth not far behind middle of fixed 

 finger. Ambulatory legs also rough with sharp granules, and with 

 tufts of curled hair above. 



Measurements. — Male (9504), length of carapace to tip of rostral 

 horn 9, width without spines 7.3 mm. 



Range. — Southern part of Gulf of Mexico and West Indies as far 

 as Barbados. Depth, 69 to 201 fathoms. 



Variation. — In some small specimens, 3 or 4 mm. long, the carapace 

 is more oblong than in the old, lateral spines stronger, dorsal sternal 

 plates subtriangular (55490, 55491, and 2651), epistomial tooth large, 

 triangular, acute, and merus of legs with a few rows of short spines. 

 This form is figured by A. Milne Edwards, 1879, but not by Bouvier, 

 1923 (pi. 11, fig. 2). Perhaps two subspecies are involved. 



Material examined. — See table, page 102. 



EUPROGNATHA BIFIDA Rathbun 



Plate 34, figs. 5 and 6 



Euprognatha bifida Rathbun, Proc. U. S. Nat. Mus., vol. 16, 1893, p. 231 

 (type-locality. Gulf of California, 33 fathoms; holotype, Cat. No. 17335, 



U.S.N.M.). ' 



Diagnosis. — No interantennular spine. Two spines side by side 

 on intestinal region. An arched lamina at each end of epistome. 

 Pterygostomian spine visible from above. 



Description. — Carapace conspicuously and coarsely granulate; a 

 spine on gastric, cardiac, and branchial regions and on first segment 

 of abdomen; two spines on intestinal region. Postocular tooth with 

 slender tip. Frontal teeth small, triangular, subacute. Antennal 

 spines slender, directed obliquely forward, equally advanced with the 

 front; a shallow, subtriangular, interantennular plate without spine. 

 A short spine on orbital arch. Lateral margins spinous; one hepatic 

 spine, two prominent branchial spines, and one spine on pterygosto- 

 mian ridge, visible in dorsal view just behind the hepatic region. 



An oblique arched lamina at each end of epistome. Sternum of 

 male and abdomen of female coarsely granulate; in both a granulate 

 raised A -shaped ridge at anterior end of sternum. 



Legs covered with spiniform granules, larger on margins of cheli- 

 peds. Palm inflated; fingers moderately gaping in proximal three- 

 fourths. First pair of ambulatory legs a little more than twice as 

 long as carapace. 



