THE CANCROID CRABS OF AMERICA 561 



the dactyli spined along inner edge. Abdomen of male with third 

 to fifth segments fused. (After Alcock.) 



Indo-Pacific region to the west coast of tropical America. 



QUADRELLA NITIDA Smith 



Plate 229 



Quadrella nitida Smith, Proc. Boston Soc. Nat. Hist., vol. 12, 1869, p. 288 (type- 

 locality, Pacheca, Pearl Islands, Bay of Panama; types in P. M. Y. U.). — 

 Rathbun, Proc. U. S. Nat. Mus., vol. 21, 1898, p. 590. 



Quadrella coronata Ortmann, Zool. Jahrb., Syst., vol. 10, 1897, p. 210 (part). — 

 Rathbun, Proc. U. S. Nat. Mus., vol. 38, 1910, pp. 586 and 617. 



Diagnosis. — One spine on wrist. No spine in old specimens at 

 lateral angle of carapace. Anterior border of carapace not deeply 

 cut, so that the spines are shorter than in coronata. 



Description. — Median sinus deeper than lateral sinuses of front. A 

 spine at lateral angle of carapace in small specimens but only a slight 

 angular projection in larger ones. Posterior edge of merus of cheliped 

 rounded, anterior edge armed with six to eight slender spines. Car- 

 pus smooth, evenly rounded on outer side and with a single short 

 spine on the anterior part of the inner side. Hands stout and con- 

 siderably swollen, especially the larger one, smooth and unarmed, 

 equalling or exceeding breadth of carapace. Fingers not gaping, 

 those of larger chela rather stout and strongly incurved, those of 

 smaller chela longer and more slender. Dactyli of legs pubescent. 



Color. — Alcoholic specimens light yellowish, fingers tinged with 

 orange and encircled Avith a median band of black (Smith). Small 

 specimens (22021) show the color of fingers extending only three- 

 fifths of length from tip and ending in an oblique line. 



Measurements. — Male (22021), total length of carapace 8.9 mm., 

 width of same 9.6 mm.; fronto-orbital width 7.6, width of front 

 between antennae 3.7 mm.; female (22021), total length 6.6 mm., 

 width 6.7 mm. 



Range. — ^Lower California, Mexico, to Panama. 6 to 31 fathoms. 



Material examined. — 



Off Cape St. Lucas, Lower California; lat. 22° 52' 00" N., long. 

 109° 55' 00" W.; 31 fathoms; rky.; temperature 74.1° F.; May 1,' 

 1888; station 2829, Albatross; 2 males, 2 females (22021). 



Genus MELYBIA Stimpson 



Melybia Stimpson, Bull. Mus. Comp. Zool., vol. 2, 1871, p. 144; type, M. thal- 

 amiia Stimpson. 



Carapace rather narrow, subquadrate, slightly convex, regions 

 faintly marked. Antero-lateral margins very short, with four teeth 

 or spines, including the orbital. Fronto-orbital width great, about 

 five-sixths the greatest width of carapace. Front about two-fifths 

 the width of carapace. Front depressed, bilobed, separated by a 

 notch from inner orbital angle. Orbits large. For tun id-like, com- 

 79856—30 37 



