406 BULLETIN 129, UNITED STATES NATIONAL MUSEUM 



MITHRAX (MITHRAX) PYGMAEUS Bell 



Plate 262, figs. 1-4 



Mithrax pygmaeus Bell, Proc. Zool. Soc. London, vol. 3, 1835 (1836), p. 172 

 (type-locality, Panama, 10 fathoms, sand; type not extant); Trans. Zool. 

 Soc. London, vol. 2, 1836, p. 55, pi. 11, figs. 3, 3f-Sh. 



Diagnosis. — Antennae long and slender. Legs slender, largely 

 smooth. Rostral lobes short, rounded. 



Description. — Carapace depressed, subovate, regions rather distinct, 

 surface smooth, lateral margin armed with two rows of spines, the 

 upper row of six beginning at the outer orbital angle, the lower row 

 of about nine, partly submarginal, beginning at the lower orbital 

 tooth and meeting the first row at the postero-lateral angle. Frontal 

 lobes short, broad, margins slightly arcuate, or sub truncate, sinus 

 V-shaped. Orbits with a minute preocular tooth and two small teeth 

 above, one at outer angle and one below. Eyes large, prominent. 

 Basal article of antennae very broad, with two marginal teeth; mova- 

 ble portion cylindrical, nearly half as long as body. For maxillipeds 

 and abdomen of male, see figures 2 and 4, plate 262. 



Chelipeds nearly twice as long as carapace; arm and wrist with a 

 few minute tubercles; hand robust, smooth; dactylus with a large 

 tubercle in the middle of the gape. Legs slender, shorter than 

 cheliped, having a few spinules on merus and carpus, propodus 

 smooth. 



Color. — Pale brownish above, reddish beneath; hands red brown. 



Measurements. — Length and width of carapace of type male 3 lines 

 (7.6 mm.). Male (2041, M. C. Z.), length of carapace 10.3, width 

 with spines 11.5, without spines 11 mm. 



Material examined. — Pearl Islands, Bay of Panama; April, 1875; 

 S. W. Garman; 1 male, 2 females (2041, M. C. Z.) ; 1 male (55117), 

 received from Mus. Comp. Zool. 



MITHRAX (MITHRAX) HISPmUS (Herbst) 



Plates 145 and 146; plate 147, fig. 3 

 CORAL CRAB 



Cancer hispidus Herbst, Natur. Krabben u. Krebse, vol. 1, 1790, p. 245 (by 



error, 247), pi. 18, fig. 100 (type-locality, not given; type in Berlin Mus.). 

 Main spini-cincta Lamarck, Hist. Nat. Anim. sans Vert., vol. 5, 1818, p. 241 



(type-locality, Antilles; type in Paris Mus.). 

 fMaja spini-cincta Say, Journ. Acad. Nat. Sci. Philadelphia, vol. 1, 1818, 



p. 458. 

 ? Mithrax spinicinctus Desmarest, Diet. Sci. Nat., vol. 28, 1823, p. 264; 



Consid. sur les Crust., 1825, p. 150, pi. 23, fig. 1. 

 Mithrax hispidus Milne Edwards, Mag. de Zool., vol. 2, 1832, cl. 7, p. (13); 



Hist. Nat. Crust., vol. 1, 1834, p. 322.— A. Milne Edwards, Crust. R6g. 



Mex., 1875, p. 93, pi. 21, fig. 1-16. — Miers, Journ. Linn. Soc. London, Zool., 



vol. 14, 1879, p. 673, pi. 13, figs. 7 and 8.— Rathbun, Proc. U. S. Nat. 



