138 BULLETIN 129, UNITED STATES NATIONAL MUSEUM 



DASYGYIUS GIBBOSUS (Bell) 



Plate 274, figs. 1-4 



Microrhynchus gibbosus Bell, Proc. Zool. Soc. London, vol. 3, 1835, p. 88 

 (type-locality, Galapagos Islands, 6 fathoms, sandy mud; holotype not 

 extant); Trans. Zool. Soc. London, vol. 2, 1836, p. 41, pi. 8, figs. 1-lc. 



Neorhynchus gibbosus A. Milne Edwards, Crust. R6g. Mex., 1879, p. 187. 



Dasygyiiis gibbosus Rathbtjn, Proc. U. S. Nat. Mus., vol. 38, 1910, p. 571. 



Diagnosis. — Carapace convex. Rostrum bifid. Extremity of male 

 abdomen narrowly triangular. Ambulatory legs diminishing in the 

 order 2. 3. 1. 4. 



Description. — Carapace convex; regions elevated and separated by 

 rather deep furrows; surface covered, particularly on each branchial 

 region, with numerous distinct, rounded tubercles resembling very 

 minute pearls. Rostrum very small and bifid. Antennae half as 

 long as body, basal article as long as rostrum, with a tooth at outer 

 angle. Antennular fossae less open than in D. depressus. Merus of 

 maxillipeds cordate, deeply notched for the attachment of the palp. 

 First segment of abdomen of male with a small tubercular tooth, 

 last segment very long, its terminal portion narrowly triangular. 



Chelipeds moderately enlarged, granulate; hand rounded; fingers 

 arched, gaping for more than half their length, denticulate at the 

 extremities, a basal tooth on the dactylus. The ambulatory legs 

 diminish in length in the order 2, 3, 1, 4; they are cylindrical and 

 hairy. (After Bell.) 



Color. — Yellowish-white. 



Measurements. — Male, holotype, length of carapace 15.2 mm. 

 (6 lines), width 12.7 mm. (5 lines.) (Bell.) 



Range. — Known only from the type-specimen from the Galapagos 

 Islands, 6 fathoms, sandy mud. 



DASYGYIUS DEPRESSUS (Bell) 



Plate 1; plate 274, figs. 5-8 



Microrhynchus depressus Bell, Proc. Zool. Soc. London, vol. 3, 1835, p. 88 

 (type-locality, Galapagos Islands, 6 fathoms, sandy mud; female, holotype 

 not extant); Trans. Zool. Soc. London, vol. 2, 1836, p. 42, pi. 8, figs. 2, 

 2d-f. 



Neorhynchus depressus A. Milne Edwards, Crust. R6g. Mex., 1879, p. 187. 



Dasygyius depressus Rathbun, Proc. U. S. Nat. Mus., vol. 21, 1898, p. 570; 

 vol. 38, 1910, p. 571. 



Diagnosis. — Carapace flattened. Rostrum simple. Extremity of 

 male abdomen broadly rounded. Ambulatory legs diminishing in 

 the order 3, 2, 4, 1. 



Description. — Carapace depressed, covered with fine granulations 

 with here and there occasional larger ones; a short stout spine near 

 the margin of the branchial region. Epimeral plates well developed 

 and produced in a spine between the second and third, and third 



