THE CANCROID CRABS OF AMERICA 311 



Clarion Island, Mexico: A. W. Anthony; 5 males, 4 females (20698). 

 Shore; Hanna and Jordan, California Acad. Sci.; 1 male, returned; 

 1 male (62702). 



Galapagos Islands; Dr. W. H. Jones, U. S. Navy; 1 male, 2 females 

 (17288). 



Eden Island, off Indefatigable Island, Galapagos Islands; rock 

 pools; April 6, 1923; Williams Galapagos Expedition; 1 male (57746), 

 received from New York Zoological Society. 



Galapagos Islands; 1888; Albatross: Charles Island; April 8; 4 

 males (22008). Duncan Island; April 13; 5 males, 7 females (22009). 



Genu.s XANTHODIUS Stimpson 



Xanthodius Stimpson, Ann. Lye. Nat. Hist. New York, vol. 7, 1859, p. 52 [6]; 

 type, X. sternberghii Stimpson. 



Carapace broadly suboval; antero-lateral marginal rim continued 

 behind widest part of carapace; postero-lateral margin up to this rim 

 shorter than chord of antero-lateral margin. Antero-lateral margin 

 lobate or dentate. Fronto-orbital distance between a third and a 

 half of extreme width of carapace. Orbits subcircular. Otherwise 

 as in Leptodius. 



Both sides of the American continent; islands of the Pacific. 



KEY TO THE AMERICAN SPECIES OF THE GENUS XANTHODIUS 



A^ Antero-lateral margins cut into four lobes or lobiform teeth exclusive of the 

 orbital angle. 

 B'. Antero-lateral margin thin. Edge of front visible in dorsal view. 



sternberghii, p. 311. 

 B^. Antero-lateral margin thick. Edge of front invisible in dorsal view. 



hebes, p. 313. 

 A2. Antero-lateral margins cut into nine or more narrow teeth. 



B'. Carapace not deeply subdivided into numerous lobules bordered with 

 hair. Median notch of front small and shallow. Wrist and hand 



rugose and dimpled above denticulatus, p. 314. 



B2. Carapace deeply subdivided into numerous lobules bordered with hair 

 anteriorly. Median notch of front deep. Wrist and hand covered 

 above with large tubercles stimpsoni, p. 315* 



ANALOGOUS SPECIES OF XANTHODIUS ON OPPOSITE SIDES OF THE CONTINENT 



Atlantic Pacific 



denticulatus stimpsoni 



XANTHODIUS STERNBERGHD Stimpson 



Plate 144; Plate 145, Figure 2 



Xanthodius sternberghii Stimpson, Ann. Lye. Nat. Hist. New York, vol. 7, 1859, 

 p. 52 [6] (type-locality, Panama; type not extant). — A. Milne Edwards, 

 Crust. Reg. Mex., 1879, pi. 45, figs. 4-46, 4c (?).3' 



Leptodius sternberghii A. Milne Edwards, Crust. R^g. Mex., 1880, p. 272; not 

 Actaeodes mexicanus Lockington.'* 



" The abdomen figured is more like that of X. hebes. 



3' The measurements given by Lockington indicate a narrower species (han sternberghii . 



