2 INTKODUCTION. 



external . In the family ScABAByEiD-^ the leaves ox* lamellae are 

 brought when at rest into close contact. In the Lucanid.e 

 (e. g. Heterochtlies, tig. 1) and Passalid.e the adjustment is less 

 perfect and the lamellae less mobile, but in the last family 

 (see Aceralus and Pasmlus, fig. 1) they are brought close together 

 by a partial rolling up of the antenna. AV' hen a fan-like form of 

 aiitenna occurs in other groups of Coleoptera, the structure of the 



Fig. ]. — Antenna! of: — 1. Accniiusrecficlois; 2. Pco^sri/ustJi/erriip/Ks; 3. Heter- 

 och/I/rs aii(hnitanciii>is; 4. PoJi/phi/lla J'lilh, male; 4 «. ditto, female; 

 ;■). I'jupoc/iruops opacicollis; 6. 2'ro.v iiidicus; 7. liolboceras calainia; 

 8. Ileliocopris bucephalus ; 9. Callinomcs bicolor ; 10. Cetonia bcjisoni. 



joints is essentially different and there is no marked dififerentiation 

 into footstalk and club. 



In a few highly modified Lamellicornia the three joints composing 

 the club have undergone a more or less complete telescoping one 

 within the other, or are otherwise modified in such a way as to be 

 no longer strictly speaking lamellate at all, but these are quite 

 evidently derivatives of the typical structure and are very 

 exce])tional. One of the most highly modified of the?e derivatives 

 is found in the genus Lethrus, belonging, strange to say, to the 

 subfamily GEOinuPiN-E, which is the only Lamellicorn group 



