140 



THE BRITISH NATURALIST. 



[July 



of the body deeply grooved longitudinally in the middle. In Gvypeta 

 lahilis the head of the male only is impressed, while in the very closely 

 allied G. cmrulea an impression is present in both sexes. The males 

 of Mnlachius cBneiis and hipustulatus, and of several species of Cis 

 (boleti, e.g.) have the head deeply and transversely impressed. In 

 the males of several Scolyti the forehead is hollowed out and the 

 surface clothed with pubescence, while in the females this portion of 

 the head is smooth and convex. The males of several beetles bear 

 upon their head horns of various degrees of development. The male 

 of Bythiiius Curtisii has a small-horn like tubercle in the middle of the 

 clypeus ; that of Odontceus mohilicornis has a long, curved, and (as the 

 specific name indicates) moveable horn on the head, replaced in the 

 female by two small prominences. In Copris lunaris the male is 

 furnished with a long slightly curved horn, itself with a small tooth on 

 each side of the base, while the female has a much shorter elevation, 

 notched at the apex — a character which is never present in any of the 

 males no matter how slightly the horn may be developed. The head 

 of the male Sinodendroii cylindvlcum bears a long recurved horn which 

 is fringed with yellow hairs towards its apex, while the female has 

 only a tubercle occupying the same situation. Many of the genus 

 Aphodius have the front of the head (clypeus) furnished with three 

 small conical elevations. These, and more especially the central one, 

 are invariably more distinct in the male, and in the female they are 

 sometimes absent altogether, sometimes replaced by a blunt elevation 

 nearer the front margm of the head, and occasionally by a slight 

 transverse elevation occupying the position of the male tubercles. In 

 the species belonging to the genus Onthophagus we meet with a 

 remarkable development of head-appendages. In the males the 

 heads tend to become somewhat longer, even shovel-shaped (nutans), 

 the back of the head is raised in the form of a vertical plate or thin" 

 ridge, from the centre of which springs a long slender horn, often 

 bent forward in the middle — (nutans, ccenobita, fracticovnis, nuchicornis). 

 In vacca the horn is straight, while in the rare taunts instead of a horn 

 springing from the middle of the plate we have the two extremities of 

 the plate developed into long curved horns like those of a Spanish ox. 

 In ovatus alone of the British species a horn is absent in the male, the 

 vertical plate or carina only being present. In the females of all the 

 British species the head is furnished with two ridges, one occupying 

 the position of the vertical plate of the male the other situated 

 between this and tlie front of the liead, but in vacca the hinder ridg'e 

 presents a small tooth at each end. In the males of some Bledii 

 [laiinis, spcctdbilis, tncurnis, luiiconii:-,, and b; cor jus) and in that sex of 

 Platystctli as covHutiis the side of liie head is elevated into a distinct 

 horn or sharp prominence— replaced by a blunt tubercle in the 



