CANCROIDEA. 



157 



A large specimen from Puget's Sound, appearing to be the same 

 species (figs. e,f, g, h) 9 is much more convex, the front more deeply 

 crenate, and the margin thicker and more deeply dentate. The pos- 

 terior lateral teeth are not quite so far back as in the productus, being 

 in the line with the median punctures, and not posterior to them. It 

 has similar outer maxillipeds, and excepting the characters just men- 

 tioned is like the productus. Length of carapax, two inches and five 

 lines; breadth, three inches and nine lines; ratio 1 : 1-55. 



Cancer productus, J. W. Randall, Journ. Acad. Nat. Sci. Philad., viii. 116. 



Subfamily XANTHINE. 



In the Xanthine, the distance between the orbits is seldom less 

 than one-sixth of the breadth of the carapax, and is sometimes more 

 than one-half; one-fourth is nearer the common ratio. The antero- 

 lateral margin is usually longer than the postero-lateral ; though 

 somewhat less in species of Panopagus, Menippe, and Liagora. The 

 third joint of the outer maxillipeds is seldom oblong, and never pro- 

 jects beyond the proper limit of the buccal area; its anterior margin 

 is commonly truncate, either somewhat obliquely or transverse, and it 

 is either arcuate in outline or slightly excavate, with occasionally a 

 well-marked emargination. But the joint is occasionally oblong, the 

 apex being produced and oblique at its terminal margin. 



Genus ATERGATIS, De Ha an. 



The genus Atergatis of De Haan (Faun. Japon., 17, 1833) corre- 

 sponds to Cancer of Edwards (Crust., i. 372, 1834), and Platypodia of 

 Bell (Zool. Trans., i. 335, 1835). Each of these authors characterizes 

 it as having the eight posterior legs of the species cristate. 



Atergatis limbatus. 



From the Feejee Islands ; also from the Sooloo Sea. 



Length of carapax of a male, 105 inches; greatest breadth 1'55 

 inches; ratio of length to breadth, 1 : 1*47. In another male, length, 



40 



