1SS9.] 7 



is fair to assume that the protective form or colouring has been ac- 

 quired since its birth, i. e., at some period during its existence ; and 

 may not a genus which exhibits this protective resemblance throughout 

 all three stages (larval, pupal and imaginal) be assumed prima facie 

 to be of more recent origin than one of which one stage only is thus 

 distinguished ? 



The Priory, Chatteris : 



November Vlth, 1898. 



ON SOME INSULAR COLEOPTERA COLLECTED BY 

 ME. J. J. WALKER, R.N., F.L.S. 



BY D. SHARP, M.D., M.A., P.R.S. 



The Coleoptera here dealt with were submitted to me several years 

 ago by Mr. Walker, who, knowing the interest I feel in Insular 

 Entomology, anticipated that I should work them out. Doing this 

 has been delayed, however, because the larger part of the specimens 

 consist of obscure forms of CurculionidcB, requiring a great deal of 

 time for their satisfactory elucidation. The descriptions of the Coly- 

 diidcs included in this paper were drawn up about ten years ago. 

 Mr. Perkins has described two species of Curculionidce, the publica- 

 tion of which will follow. The other species of that family contained 

 in Mr. Walker's collection must still wait for determination. They 

 consist chiefly of Cossonides, a subfamily of great difficulty, and of 

 which no collection containing many authentic types is available to me. 



Fam. COLTDIID^. 



XUTHIA PARALLELA. 



Xuthia parallela, Sharp, Journ. Linn. Soc. Zool., xix, 1885, p. 70. 



Resolution Bay, Taou-ata Island, Marquesas ; seven examples. 

 Also a fragment from 0-Hiva-oa Island. 



These specimens do not differ in any respect from Japanese 

 exponents. 



BiTOMA DISCICOLLIS, n. Sp. 



Latiuscula, suhdepressa, opaea,fusca, antennis pedibusque testaceis, ely- 

 tris rvfis', nigro-variegatis. Long., 3| — 4 mm. 



Antennae with large, abrupt, two-jointed club. Head dull, rounded in front, 

 without distinct sculpture, but with a few depressed flavescent setae, and a fine 

 straight carina along the inner margin of each eye. Thorax transverse, on each side 

 with two raised costae, the sides esplanate and minutely crenate, the disc deplanate, 

 sub-impressed ; the surface finely granulate, and bearing minute, depressed, flaves- 

 cent setae. Elytra of a dull red colour, but much marked with black ; the black 



