278 BULLETIN 97, UNITED STATES NATIONAL MUSEUM. 



inner face of large palm strongly protuberant on the upper half; its 

 supero-distal part tuberculate. Fingers stout and rather stumpy, 

 with a small .gap between them, tips broadly excavate. 



Legs densely hairy on the lower surface of the propodi and proxi- 

 mal end of the dactyli. Merus joints armed above with a tooth. Legs 

 very granule us; the marginal spinules of the last three segments are 

 very fine and numerous. 



First segment of male abdomen transversely cristate; second seg- 

 ment not so wide as the third. 



Measurements. Male holotype, median length 32, width 37, antero- 

 lateral width 23, approximate length of legs, first 48, second 60, third 

 62, fourth 50.5 mm. 



Range. Known only from Jamaica. 



Material examined. 



Montego Bay River, Jamaica: 2 feet, stony bottom; Aug. 1, 1910; 

 C. B. Wilson; 1 male (42881). Fresh water; Aug. 25, 1910; E. A. 

 Andrews; 1 female (41524). 



Kingston Harbor, Jamaica; T. H. Morgan; 1 male holotype 

 (17226). 



Genus PLATYCHIROGRAPSUS de Man. 



Aspidograpsus KR0YER. MS., Copenhagen Museum ; type, A. tj/plcus Kr0yer. 

 Platuchiruyrapsua UE MAN, Zool. Ana., No. 50G, 180G, p. 292 ; type, P. tpcc- 



tabilia de Man. 



Very near Glyptoyrapsus. Differs as follows : The labial border is 

 riot straight in front view, but the two halves are arched upward. 

 The outer muxillipeds have between them a narrow rhomboidal gape 

 and are further from the epistome. 



The propodus of the large cheliped is prolonged proximally far 

 beyond its articulation with the carpus, and its outer surface is per- 

 fectly flat. 



Fluviatile (in part, at least), inhabiting the Atlantic slope of 

 Mexico, and also West Africa. 



PLATYCHIROGRAPSUS TYPICUS Rathbun. 



RIVER CRAB. 

 Plate 73 



Aspidograpsus typicus KK0YEU, MS., Copenhagen Museum; Bay of Mexico. 



Pla,tuc-liirn!/i-np*iiN xpei-tnliilix RATIMM'N (part). Proc. U. S. Nat. Mus., vol. 

 22, 1000. p. 279; not P. 8peciubili de Man, 1S9G. 



Plalycliiruyriipxiis ij/picus KATHWN, I'roe. U. S. Nat. Mus., vol. 47. 1914, 

 p. 122. text-fifr. 3, pi. 5 ( tyjte-localit.v. Macuspana River. Montecristo, 

 Tabasco. Mexico. 140 miles from the sea, altitude over 100 feet; holo- 

 type, Cat. No. 237G1, U.S.N..M.). 



Diagnosis. Palm prolonged far beyond articulation with wrist 

 Dactylus of fourth leg very broad and flat. 



