4o6 REPORT OF NEW JERSEY STATE MUSEUM. 



case of lesser cheliped. Carpus broad, with groove to its distal 

 edge, though spine at inner anterior corner. Merus about equals 

 carpus. Ambulatory feet similar, two median pairs little longer, 

 fourth shortest and border widely on third abdominal segment. 

 Fused segment of narrow abdomen in male with distal two- 

 thirds nearly straight, rest curves outward each side. Penul- 

 timate abdominal segment with straight sides, and terminal seg- 

 ment rounded at end. 



Color brownish above, paler below. Chelipeds more brownish, 

 paler below, and fingers blackish, turning pale bluish in preserved 

 examples. Length of carapace 30 mm., width 42 mm. 



Remarks. — This species occurs from Long Island Sound to 

 Brazil along our Atlantic coast, but is not common north of 

 New Jersey. It is easily distinguished from any of our other 

 related mud crabs, not only by its large size, but by the tubercle 

 on the subhepatic region just below the front lobe of the anterior 

 lateral edge of the carapace, by the postorbital tooth being sepa- 

 rated from the second tooth of the antero-lateral edge by a 

 rounded sinus, and by the dactylus of the larger cheliped having 

 a stout tooth near the base within. 



These crabs live on the oyster-beds and in our bays and sounds, 

 where they are often dredged up by the oystermen. My ex- 

 amples from Beesley's Pont, collected miany years ago by Samuel 

 Ashmead. The species attains a larger size than noted above, 

 examples with the carapace 40.6 mm. long and 62 mm. wide, 

 being known. Mr. Witmer Stone found it at Point Pleasant. 



Genus EURYTIUM Stimpson. 



Eurytium Stimpson, Ann. Lye N. Hist. N. Y., VII, 1859, p. 56. Type Cancer 

 Umosa Say, virtually monotypic and designated. 



Carapace broad, length about two-thirds its width, convex, 

 region slightly marked, without transverse raised lines. Antero- 

 lateral borders regularly arcuate, shorter than postero-lateral, 

 cuit into five shallow teeth, second tooth rounded and intimately 

 fused with first. Fronto-orbital border over half carapace width. 

 Front from a fourth to almost third carapace width. Front 



