Insects. 



8015 



thinking that the antennae are thus described in order to make this 

 insect fit into Leach's division of Trichiosoraa, one of the six sub- 

 genera into which this author, without any necessity, divides the 

 genus Cimbex of Olivier. These sub-genera are founded on differ- 

 ences in the antennae, the labium, and the femora ; but the charac- 

 teristics are so uncertain, one form passing into the other, that it is 

 better to abandon these divisions. A proof of this is to be found in 

 the antennae of our insect, these organs having very distinctly but 

 seven joints, and the fifth joint belonging in some measure to the 

 club ; the seventh and eighth joints of Westwood are one joint, there 

 not being even a trace of suture to be seen. 



The thorax is shining black, with dense ferruginous pubescence. 

 The legs are black to the ends of the tibiae, thence reddish yellow. 

 Coxae and femora clothed with long [velvety hairs ; in the male the 

 femora of the intermediate and hind pair are spined. The wings have 

 a yellowish tint, which is darker towards the costal nervure ; they are 

 black at their insertion ; the post-costal, externo-medial and anal 

 nervures are yellow ; stigma brownish black ; on the outer edge are 

 some smoke-coloured nugae, which are darker in some individuals than 

 in others. The abdomen is black, in the male elliptical or cylindric, 

 in the female broader and flatter, having in both sexes a ferruginous 

 pubescence at the base and under side, and a gray pubescence on the 

 top (fig. 10). 



The saw and ovipositor (represented in profile at fig. 13) have pre- 

 cisely the same general appearance as in the very nearly allied spe- 

 cies, C. variabilis, the largest of our indigenous species, only there is 

 a difference in the shape of the projections on the edge, which are 

 not mushroom-shaped, but depressed leaf-shaped protuberances, re- 

 presented very highly magnified at fig. 14. The difference between 

 this species and C. Lucorum is but small ; the latter is somewhat 

 larger and a bolder insect ; and, moreover, in C. Lucorum all the 

 tibiae are red, and only the knee or upper extremity brown. Sup- 

 posing De Geer's description of the larva to be correct, and not to 

 belong to any other species, then the larva of C. Lucorum has no spot 

 on the crown of the head. I hope to be fortunate enough to meet 

 with this larva in our own country ; 1 imagine it lives on the birch. 



C. Betuleti is not rare in this country: the larva has been more 

 than once sent to me in some numbers from Utrecht, by Dr. Verloren. 

 I have myself taken it near Leyden. Mr. Dozy met with it at Breda. 



