l68 SMITHSONIAN MISCELLANEOUS COLLECTIONS 



Genus ETHUSi\ Roux 

 274. ETHUSA SEXDENTATA^ (Stimpson) 



Plate XIX, Fig. 4 



Dorippe sexdeniata Stimpson, Proc. Acad. Nat. Sci. Pliila., x, p. 163 

 [61], 1858. 



Of this small species a single male individual was obtained. It 

 presents characters which may, upon further examination, warrant 

 its separation from the typical Bthusa. The carapax is narro\fed 

 forwards; proportion of breadth to length, i : 1.13. The surface is 

 uneven, but not granulated. Inter-ocular front cjuadridentate ; teeth 

 very sharp, subequal, in two pairs separated by the median notch. 

 Extra-ocular teeth sharp and spiniform, about equal to the frontal 

 teeth in size, but not reaching to the level of their tips. Infra- 

 orbital spine obsolete. External maxillipeds naked, longitudinally 

 sulcated ; meros nearly as broad as ischium. Inner maxillipeds as 

 in Dorippe. The epignath of the outer maxillipeds plays in a large 

 afferent cavity at the base of the pterygostomian region, which is not. 

 however, separated, as in Dorippe, from the open space at the base 

 of the chelipeds. The feet are slender, rounded and roughened with 

 slight asperities. 



In life carapax pale yellowish-gray ; feet pale brownish ; fingers of 

 the hand white. Dimensions of the carapax : Length, 0.275 '' 

 breadth, 0.242 inch. 



It was dredged from a shelly bottom in twent}' fathoms, in Kago- 

 sima Bay, Japan. 



Genus TYMOLUS Stimpson 



Body oblong. Carapax much shorter than the body, rounded. 

 abruptly contracted anteriorly, the facial region being narrow and 

 protruding. Hepatic and branchial regions ample, swollen. Affer- 

 ent branchial opening normal in position, at the anterior base of the 

 chelipeds. Front quadridentate. Between the median teeth of the 

 front a small tooth may be seen from above, which constitutes the 

 wall of the apex or anterior extremity of the buccal area and en- 

 closes the tips of the outer maxillipeds. Orbits deep, longitudinal ; 



^This species was first transferred to the genus Etiuisa by Stimpson, on the 

 cover of one of the separates of the "Prodromus" (teste S. I. Smith). 



