266 S. I. /Sinith — Tropical and Siib-tropical 



clearly the form of the young Ocypode within the megalops skin and 

 to establish unequivocally my former conclusion that Say's Mono- 

 lepis inerrnis is really the megalops-stage of this species of Ocypode. 



I have examined a very large series of specimens of the adult form 

 of this species from Brazil ; St. Thomas ; A spin wall ; Nassau, New 

 Providence ; Texas ; Key West, and Sarasota Bay, Florida ; the Ber- 

 mudas ; North Carolina ; New Jersey ; and the south shore of Long 

 Island : and, between specimens of the same size, I can find no dif- 

 ferences which could be regarded as specific, though young specimens 

 difier much from adults, and these differences have probably led to 

 the admission of the two nominal species, arenaria and rhonibea. 



This species is evidently the 0. quadrata of Fabricius : the orig- 

 inal description of Cancer quadratiis agrees in every respect, and the 

 comparison with C. ceratophthalmus ("Aftinis C. ceratophtalmo at 

 oculi simplices ") and the habitat ought to leave no doubt whatever 

 on this point. DeHaan, however, refers Fabricius' species to a Japan 

 Sesarma [Grapsics [Pachysoma) quadratus DeHaan, Fauna Japonica, 

 p. 62, pi. 8, fig. 3), although he had already (op, cit., p. 29) retained 

 it in the genus Ocypode. Succeeding authors have failed to restore 

 Fabricius' species to its proper place. Fabricius' Ocypode rhotnbea^ 

 of which the habitat was unknown, is certainly not this species, nor of 

 the genus Ocypode in the modern sense, as the first line of the diag- 

 nosis, " thorace laeuiusculo utrinque unidentato," plainly shows. If 

 ante-Linnean names, when occasionally binomial, are to be adopted, 

 then Catesby's arenarius may be retained. 



When writing the report on the Crustacea of Vineyard Sound, I 

 bad not been able to consult Fabricius' works, and stated that "the 

 Brazilian species, usually called rhomhea appears to be identical with 

 oiirs, and if it is really the rhomhea of Fabricius, his name should 

 undoubtedly be retained." This remark is quoted verbatim in order 

 to correct Mr. Kingsley's statement (Proc. Acad. Nat. Sci. Philadel- 

 phia, 1878, p. 322 (7), 1878) that I say "that our form seems to be 

 identical with the Brazilian one, which is known as 0. rhomhea Fab- 

 ricius, in which case the name rhomhea will hold." 



G-rapSUS pictUS Lamarck. 



Cancer grapsus Linne, Systema Natura\ ed. xii, i, p. 1048, 17 G7; Amcenit. Acad., 

 2d ed., iv, p. 252, pi. 3, fig. 10, 1788. 

 Herbst, Krabben imd Krebse, i, p. 115, 1782. 



J. C. Fabricius, Systema Entomologise, p. 406, 1775; Entomologia System., ii, p. 

 438, 1793 ; Suppl. Entom. System., p. 342, 1798. 



