Zoological Society. 223 



of the small hairs which give the brownish colouring to the other 

 species here described. 



Adioristus subdenudatus. Ad. oblongus, niger,pilis minutissimis 

 atque squamulis albescentibus adspersus ; antennis tarsisque fus- 

 cescentibus ; rostro carinato, punctulato ; capite inter oculos trans- 

 verslm impresso, crebre punctulato ; thorace subcylindraceo in 

 medium paulo dilatato, punctis minutis impresso ; elytris oblongo- 

 ovatis, punctato-striatis, interstitiis paulb convewis, obsolete punc- 

 tulatis. 



Long. corp. et rostri, 6 J lin. ; lat. 2 J lin. 



Hab. Mendoza. 



This insect is intermediate in size between the Ad. punctulatus 

 and Ad. angustatus, and is readily distinguished from either of the 

 species here described by its denuded appearance ; the scales and 

 hairs, which are sparingly scattered over the body, only become visi- 

 ble with the assistance of a moderately strong lens. 



The rostrum is about twice as long as the head, very thickly 

 though finely punctured, and the punctures are confluent; in the 

 middle is a distinct carina. The head is separated from the rostrum 

 by a transverse and somewhat shallow depression, and in the middle 

 of this depression is a small fovea : the upper surface of the head, 

 as well as the thorax, is very thickly and finely punctured, and the 

 punctures are confluent. The thorax is rather broader than long, 

 subcylindrical, truncated before and behind; the upper surface is 

 slightly convex, and the sides are somewhat rounded, being slightly 

 dilated a little in front of the middle. The elytra are of an elongate- 

 oval form, moderately convex, somewhat attenuated at the apex, 

 but with that part rounded ; they are distinctly punctate -striated ; 

 the punctures are arranged closely together, and the interstices of 

 the striae are narrow, slightly convex, and very delicately punctured. 



Cylydrorhinus angulatus. — Under this name M. Guerin-Meneville 

 describes, in the ' Revue Zoologique ' (No. 7, 1841, p. 217), a species 

 of Curculio, from Port Famine, which I am inclined to regard as 

 specifically identical with specimens brought by Mr. Darwin from 

 St. Cruz and St. Julian. 



M. Guerin states that the elytra are covered above with large 

 deep punctures arranged in longitudinal striae, at the base of each 

 of which is a very small tubercle, and which are united together by 

 an indistinct transverse impression. 



In the specimens brought by Mr. Darwin, the elytra are deeply 

 punctate -striate at the base, but from the base towards the apex the 

 punctures gradually decrease in size ; the minute tubercles are situ- 

 ated on the anterior margin of each puncture, and in addition to the 

 striae of punctures, the elytra are for the most part covered with 

 somewhat irregular transverse rugae ; these are most distinct on the 

 sides of the elytra (or rather what appears to be the side, for the 

 elytra are strongly keeled at some little distance from the lateral 

 margin, so that that part is hidden as we view the insect from above), 

 less distinct on the apical portion, and do not extend to the disc. 

 The apical portion of each elytron is slightly produced, and the 



