138 SMITHSONIAN MISCELLANEOUS COLLECTIONS 



on its inner margin, slender and half concealed beneath the en- 

 dognath, the portion next the ischinm only being exposed to view : 

 endognath broad, ischium quadrate ; meros-joint equaling the 

 ischium in length and much broader than long, broadly auriculated 

 at the external angle, the auricle protruding forward and not side- 

 ways ; palp prosarthroid, inserted at the bottom of the sinus in the 

 anterior side of the meros. Chelipeds rather small and weak, un- 

 armed ; those of the female with fingers resembling those of the 

 female Gelasimns. Ambulatory feet slender, unarmed, smooth, 

 pubescent near the base; meros-joint with a ridge on the posterior 

 surface parallel \vith the superior margin ; dactyli slender, obliquely 

 compressed, shortly ciliated. Sternum broad ; its posterior joint 

 widely exposed on either side of the abdomen, its arcuated anterior 

 margin next the mouth projecting, laminiform, like a septum, for the 

 better separation of the mouth from the extremity of the abdomen. 

 Abdomen of the male somewhat tapering, but not dilated at the 

 base, strongly constricted or sinuated on each side at the middle : 

 terminal joint not narrower at the base than the penultimate joint. 

 The male abdominal appendages of the tirst pair are long, slender, 

 bent or geniculated beyond the middle, where there is a strong- 

 tubercle or i)apilla on the convex side, and contorted toward their 

 extremities ; those of the second pair slender, minute. Abdomen of 

 the female broad, covering the whole of the sternum with the excep- 

 tion of its postero-lateral corners; terminal joint broad and scarcely 

 free, the sides of the penult joint being a little expanded so as to 

 enclose its base in a shallow sinus. 



This genus inhabits the Chinese seas. 



In the form of the carapax approaches somewhat Cyrtoi^raf>si(s 

 Dana, but the characters of the male abdomen, length of eyes, etc.. 

 would remove it from the Grapsidcc. 



231. CAMPTANDRIUM SEXDENTATUM Stimpson 



Plate XVI T, Fig. 4 



Camf'faitdriiitii scxdeiitaiiiiii Stimpsox. Proc. Acad. Nat. Sci. Phila., x, 

 p. 107 [53]. 1858. 



The trivial characters of this species may be gathered mostl\' from 

 the generic description preceding. Reprehensible as the practice 

 which we now follow may be in general, it was thought advisable in 

 the present case, where the characters of the animal exclude it from 

 all known families, by which their generic or specific value might be 

 determined. We have therefore given under the head of the genus 



