CRUSTACEA NORTH PACIFIC EXPLORING EXPEDITION 53 



at last entirely disappearing, while in other characters the specimens 

 remain exactly the same. And the figure of C. exaratus, in the 

 "Voyage au Pole Sud," certainly presents the characters usually 

 assigned to C. sanguineus. Among our specimens it is not difficult 

 to find forms agreeing with De Haan's Xantho Uvidus and A^. aMnis; 

 and these are so connected by intermediate forms that they cannot be 

 specifically separated. Every degree of extent in the front and in 

 the hiatus of the fingers, between the extremes represented by these 

 two varieties, may be found among our specimens. The Xantho 

 distill gxiendus certainly appears at first entirely distinct, the gran- 

 ulation of the carapax and hands, and particularly the sculpture or 

 erosion of the ambulatory feet, seeming to be characters which 

 it would be in vain to seek for in any variety of C. exaratus. But 

 we have before us specimens of this form from Hongkong which 

 show gradations toward the type. In some of these the carapax is 

 rather broad, with little or no granulation and a protruded front. 

 In others the granulation of the hand disappears, while that of the 

 carapax remains the same. In others all granulation disappears, 

 and among all these specimens there are some which possess the 

 supplementary tooth, while in others it is wanting. 



Future observers, aided by a still greater number of specimens 

 than is now accessible, may succeed in finding constant characters 

 upon which good species may be founded, but the present indica- 

 tions certainly require us to regard as varieties the several forms 

 now to be described. 



Var. a, SANGUINEUS 



With a. distinct supplementary tooth, formed by the division by a 

 sulcus of the posterior edge of the lateral tooth of the margin ; this 

 is much more distinct in the adult than in the young. The antero- 

 lateral teeth are sufficiently prominent, anterior ones blunt. Front 

 much undulated, rather narrow (in extent just half that of the 

 antero-lateral margin), and scarcely protruded beyond the edge of 

 the orbit. Surface of carapax areolate, areolets rather smooth and 

 glossy, shining. Upper and outer surface of chelopoda with reticu- 

 lating rugse. Pincers sometimes much curved, moderately gaping, 

 inner edges well toothed ; color black, tips white. Ambulatory feet 

 smooth, edges hairy; penult and antepenult joints obsoletely grooved 

 above ; dactyli granulose. 



Found at the Sandwich Islands and at Loo Choc. 



