Genera of the Cossonidcs. 573 



and the underside being (at any rate in the example now 

 before me) piceous, with the limbs of a still clearer tint. 



91. STEREODERUS (nov. gen.}. The present genus is 

 manifestly allied to Stereoborus and Stereotribus, though 

 the rather smaller size to'which its members would appear 

 to descend, added to their more convex, cylindrical bodies, 

 more lightly sculptured surface, and their more conical, 

 unimpressed prothorax, gives them more the appearance 

 at first sight of such forms as Xestoderma and Xestosoma 

 (which are equally dark and highly-polished, and have a 

 broad, abbreviated rostrum) in the vicinity of the Rhyncoli. 

 Nevertheless, the peculiar construction of its rostrum, 

 which is often barbed beneath with long fulve scent hairs, 

 and has three small clefts in the upper anterior excavation 

 which receives the labrum, as well as a curious tendency to 

 be armed with one or more tubercles in the centre behind 

 (all of which exist, more or less modified, in Stereotribus), 

 is too significant to be misunderstood. And when we add 

 to this the characteristic shortness of its scape, the exces- 

 sive robustness of its limbs, and the internally dilated 

 basal half of its anterior tibias (the superadded triangular 

 portion arising from a robust spinule, situated at some 

 distance behind the spiniform inner angle), each of which 

 is conspicuously expressed in that genus, there can be no 

 longer the slightest room for doubt as to its true affinities. 

 Its eyes are large, very wide apart, and somewhat anterior 

 in their position ; and its third tarsal joint, as in most of 

 these immediate groups, is simple. 



Stereoderus is a genus which would seem to have a 

 rather extended geographical range, out of the three 

 species now before me (all of which are from the collection 

 of Mr. Pascoe), two having been captured by Mr. Wallace 

 in the islands of the Malayan archipelago, whilst the other 

 is from the Fiji islands in the Pacific. The latter, how- 

 ever, although I think it is impossible to regard it as 

 generically distinct, shows a slight structural difference in 

 the minute emargination at the extreme apex of its 

 rostrum, the large medially-cleft lobe, which nearly fills 

 up the cavity in the other two species (causing the whole 

 central piece to appear trifid) being so short, small, and 

 entire as to be strictly obsolete. But so diminutive a 

 character, even though structural, can scarcely be regarded 

 as more than a trivial one. 



s s 2 



