l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS 



sharp tooth near the extremity, being one of three large teeth sur- 

 rounding the insertion of the carpus. Superior and inferior edges 

 of ambulatory feet somewhat setose ; the penultimate joints of these 

 feet, however, are smooth and slender. In this and the other known 

 species of the genus the setae are stout and clavate in form. 



The dimensions of a sterile female are : Length of carapax, 0.65 ; 

 greatest breadth, 0.51 inch. 



This species was dredged in the harbor of Hakodadi, Island of 

 Jesso, Japan, on a bottom of weedy sand, at the depth of 6 fathoms. 



Only one other species of the genus is known, S. acutifrons Dana, 

 which inhabits the opposite coast of the North Pacific. 



Genus DIONE De Haan 



15. DIONE AFFINIS ' De Haan 



Dionc a-fHnis De Haan, Fauna Japonica, Crustacea, 94, pi. xxii, fig. 4. 



The only specimen taken is young, the dimensions of the carapax 

 being: Length, 0.57; greatest breadth, 0.41; breadth between prse- 

 orbital spines, 0.35 inch. Proportion of this interorbital breadth to 

 the length, i :i.63. This proportion in De Haan's figure is i :i.93. 

 Our specimen dififers from those described by De Haan in its more 

 depressed form, its narrower and smoother carapax and broader 

 front. There is no tooth within at the base of the movable finger 

 and none on the outer base of the hand. The horns of the rostrum 

 are longer than in the adult D. affinis, and the abdomen of the male 

 is not dilated near the base. 



Having no opportunities of comparing our specimen with the 

 young of the species to which it is here referred, we do not venture 

 to consider it distinct. 



It was taken in a harbor on the northwest coast of the Island 

 of Ousima. 



Genus MITHRAX Leach 



16. MITHRAX SUBORBICULARIS "- Stimpson 



Plate IV, Fig. i 



Mithrax suhorhicidaris Stimpson, Proc. Acad. Nat. Sci. Phila., ix, p. 218 

 [25], 1857. 



This species belongs to the division "Mithrax transversaux" of 

 Milne Edwards. The following description is taken from a sterile 

 female, the only specimen found. Carapax rounded, not narrowed 



^ Schizophrys aspej-a (Milne Edwards). 



" Cyclax (Cydoinaia) siiborbiciilaris (Stimpson). 



