INTRODUCTION. XXV 



di'ical, conipressed, or flattened and dilated; tlicir shape may 

 be globular, cylindrical, triangular, or cordiibrm ; frequently the 

 penultimate joint is eniarginate or bilobed. From the under side 

 (;f the joints in some families there arise appendages more or less 

 membranous in structures, called tanked lobes. In some rare cases 

 a joint is prolonged from its upper edge so as to cover the follow- 

 ing joint. The under side or sole of the tarsus is variously clothed 

 with spines, hairs, spongy pubescence, or lamellae; the nature of 

 the vestiture is often an indication of the sex. It is also quite 

 common to find the anterior and often the middle also dilated in 

 the males. 



The claws, usually two in number, are also variable in form 

 and structure, and give many characters for the distinction of 

 genera and species ; they are usually freely and independently 

 movable, but in many instances they become united at base, and 



Natatori.\i, Legs: 1. Dineutus ; 2. Cylnster. Fossorial: 3. Copris. TiBiiE: 4. Un- 

 ffviiculate, Rhynchophorns ; 5. Mucronate, Cossonus ; 6. Closed corbels, Eupagoderrs : 

 7. Open corbels, Brachyderes. Tarsi: 8. Lobed beneath, Dicrepidius ; 9. Lobed and 

 with onychium,.Saudalus. Ci.aws or Ungues : 10. Pectinate, Odontonyx ; 11. Serrate, 

 Melanotus; 12 Toothed, Lachnosterna ; VX Toothed and serrulate, Listrochcliis ; 14. 

 Cleft with equal movable parts, Cantharis ; 1.5. Unequally cleft, Phytalus; 16. Bifid also 

 toothed, Ectopria; 17. Cleft and divaricate, Rhynchites ; 18. Connate at base, Attela- 

 bns; 19. With membranous appendages, Placonycha ; 20. Chelate, Phisiotis. 



even nearly to the tip, tliey are then called coimafe. Instances 

 rarely occur of the presence of one claw only; numerous examples 

 are, however, seen of a greater or less inequality of size and even 

 structure between tiie two claws, as iu some Pselaphid;i3, and 

 the males of some ScarabseidiE. When the claws arise from the 

 joint in such a manner that they diverge but little, they are called 

 divergent ; when, however, each arises from an opposite side of 



