THE CRUSTACEA OF NEW JERSEY. 445 



tember 20th, 1904, by Mr. H. L. Viereck. These examples 

 closely resemble Pachygrapsus transversus in the outer faces of 

 the maxillipeds, but differ at once in the quadrate carapace. 

 From Sesarma reticulatmn they differ at once in having the 

 maxillipeds with smooth surfaces, Sesarma having a piliferous 

 ridge crossing the merus and ischium on their external faces. 

 Mr. Viereck tells me that these specimens, as far as he can 

 recollect, were picked up on the beach, doubtless waifs from some 

 more tropical region. This addition to the fauna of New 

 Jersey is, therefore, of interest. 



Family OCYPODID.E. 



The Ghost Crabs. 



Carapace generally moderately convex, either cancroid or 

 trapezoidal, with antero-lateral edges straight or arcuate, bran- 

 chial regions not generally dilated. Front of moderate width or 

 very narrow. Orbits and eye-stalks of moderate size or greatly 

 developed. Chelipeds in adult male generally of moderate size, 

 sometimes slender and elongate. Seventh joint in walking legs 

 styliform, without strong spines. Pleon not always covering- 

 whole width of sternum between last pair of legs. 



Crabs inhabiting our sandy beaches, or muddy or marshy flats 

 near the sea. 



Key to the genera. 



a. Eye-stalks slender; chelas in male extremely unequal. UCA 



aa. Eye-stalks stout; chelas in male somewhat unequal. ocypodE 



Genus Uca Leach. 

 TJic Fiddler Crabs. 



Uca Leach, Edinb. Encycl., VII, 1814, p. 430. Type Ocyl^oda heterochelos 

 Lamarck. (Not consulted.) This, however, designated by M. J. Rath- 

 bun, Ann. Inst. Jamaica, I, 1897, P- 28. 



Gelasimus (Buffon) Latreille, Nouv. Diet. Hist. Nat., XII, 1817, p. 517. Type 

 Ocypoda maracoani Latrielle, first species. 



