- 



.b 



XVIII. On the Genera of the Cossonidaa. 

 By T. VERNON WOLLASTON, M.A., F.L.S. 



[Read 2nd June, 1873.] 



HAVING determined during the past winter to examine 

 critically the structural characters of the various genera 

 of the Cossonidcs (so far as accessible) which have hitherto 

 been published, I soon perceived that a very small pro- 

 portion of the numerous species which were submitted to 

 me could by any possibility be embraced by the 29 groups 

 which were acknowledged by Lacordaire, and which have 

 been admitted subsequently (with two or three additions) 

 into the Munich catalogue. And moreover the excessive 

 inaccuracy of the greater number of the diagnoses, as 

 given by Lacordaire ( for which however he was not 

 himself responsible, they having simply been epitomized, 

 at times perhaps somewhat in haste, from the different 

 authors by whom they were originally compiled), made it 

 but too evident that, in order to define them aright, no 

 asserted peculiarity could be trusted as necessarily true, 

 but that every single feature would have to be collated 

 afresh, and on an independent basis. This being the case, 

 it will at once be seen that my object in the present memoir 

 has not been to monograph the species ; and therefore in 

 two or three extensive and well-established genera, such as 

 Cossonus and Rhyncolus, I have been content to select a 

 few types, from distant parts of the world, and to treat 

 them as representing their respective groups. Yet this 

 very method of proceeding has involved the necessity of 

 examining at any rate certain species with the utmost 

 care ; and as an accurate list of these will be found at the 

 close of my paper, it follows that the members of the 

 family which are there catalogued (amounting to 253) 

 may be looked upon as arranged systematically in accord- 

 ance with my own views. 



At the same time I would not intend to imply that no 

 other representatives of the groups which are more par- 



TRANS. ENT. SOC. 1873. PART IV. (OCT.) I I 



M368682 



