422 



BULLETIlv" 129^ UNITED STATES NATIONAL. MUSEUM 



MITHRAX (MITHRACULUS) SCULPTUS (Lamarck) 



Plate 152 



Cancellus rugosus, pedibus hirtis Petiver, Pteri-graphia Americana, 1715, 



No. 368, pi. 20, fig. 6. 

 Araneus marinus Seba, Thesaurus, vol. 3, 1758, p. 49, pi. 19, figs. 22 and 23. 

 Maia sculpta Lamarck, Hist. Anim. sans Vert., vol. 5, 1818, p. 242 (type- 



localjity not given; type in Paris Mus.?); ed. 2, 1838, p. 436. 

 Mithrax sculptus Milne Edwards, Mag. de Zool., vol. 2, 1832, pi. 5; Hist. 



Nat. Crust., vol. 1, 1834, p. 322.— Rathbun, Proc. U. S. Nat. Mus., vol. 



15, 1892, p. 271, and synonymy. — Gundlach and Torralbas, An. Acad. 



Habana, vol. 36, 1899 (1900), p. 330, text-fig.; reprint, 1917, p. 17, pi. [4], 



fig. 9. 



Mithraculus coronatus White, List Crust. Brit. Mus., 1847, p. 7 (part); no* 



Cancer coronatus Herbst. 

 Mithrax minutus Saussuri;, Mem. Soc. Phys. de Geneve, vol. 14, 1857, p. 



425, pi. 1, fig. 1 (type-locality, Antilles; type in Geneva Mus.). 

 Mithraculus sculptus Stimpson, Amer. Journ. Sci., vol. 29, 1860, p. 132. — 



A. Milne Edwards, Crust. Reg. Mex., 1875, p. 105, pi. 20, fig. 2. 



Diagnosis. — Posterior two- 

 thirds of carapace nodose. Four 

 antero-lateral lobes. Wrist 

 smooth, non-dentate. Color 

 greenish or bluish. 



Description. — Carapace 

 broader than long, with arcuate 

 margins. Front broad, little 

 advanced, formed of two shallow 

 lobes separated by a narrow 

 notch. Inner orbital angles ob- 

 tuse and slightly produced. 

 The orbital border bears three 

 tubercles — one small superior, 

 one external, the other inferior. 

 Basal article of antenna very 

 wide, much expanded outwardly, 

 forming a part of floor of orbit ; 

 its antero-external angle is tuberculiform and scarcely more advanced 

 than superior inner orbital angle. Posterior two-thirds of the carapace 

 nodose; branchial regions crossed by oblique sulci, the intervening 

 elevations being broken up into irregular lobulations. Antero-lateral 

 margins cut into four rounded lobes, which in the young are more 

 or less pointed. Carapace and chelipeds naked and shining. 



Chelipeds enlarged in the male; the arm has two spiniform tubercles 

 in front; carpus smooth and round; hand compressed; dactylus as 

 long as palm; fingers mdely gaping, each provided with a large tooth, 

 that is near the base in the dactylus, but in the middle of the gape in 

 the pollex; in the female the fingers gape less and are without large 



Fio. 125.— Mithrax (Mithraculus) sculptus, male 

 (14058), maxilliped, X 11.8 



