466 CLASS vni. 



Simple eyes are not present in the generality of these insects; they 

 occur however in some; two are met with in many small JSrachelytra, 

 species of Anthophagus and Omalium (see KLUG, cited above, 

 p. 280), and in Paussus bucephalus; and according to CURTIS one is 

 found in the middle of the head in some Dermestidce (WESTWOOD, 

 Introd. to Mod. Classif. Yol. I. p. 35). The antennae have a very 

 different form and length, but consist commonly of eleven joints. 

 The anterior thoracic segment is large and moveable ; the middle and 

 last segments of the thorax are entirely covered above by the shield- 

 covers. The under wings are absent in some species, which natu- 

 rally also in that case are not able to fly, since the shield-covers are 

 not used for flight ; these last are never wanting, but are sometimes 

 very short. The integuments of the body are commonly hard, but 

 less so on the dorsal surface, inasmuch as it is covered by the elytra. 

 These insects undergo a perfect metamorphosis. The larva resem- 

 bles a worm, and commonly has six horny feet *. Some larvae (Cur- 

 culio, Cerambyx) have no feet, but membranous tubercles in theii 

 stead. 



Of the diffusion of this order an idea may be formed when we 

 reflect that, according to LATREILLE, more than fifteen years age 

 about 30,000 species of beetles were known 2 , and, according tc 

 WESTWOOD, in 1839, 28,000 were found in the British Museum 

 alone. And how many species have there not been since then, anc 

 are there not almost daily discovered ! 



The number of joints in the tarsus was first made use of 

 GEOFFROY for the division of this order (Hist, abregee des Insectes, i 

 pp. 50, 51), who was followed by OLIVIER (Enc. method., Hist. n. d 

 Ins. Tom. v. 1791, p. 107), LATREILLE, DUMERIL, and nearly al 

 modern writers ; a character, of which some have exaggerated th< 

 value (see ex. gr. ILLIGER in his Magazin. f. Insektenkunde, i. 1802 

 s. 285), but which has some exceptions 3 , and moreover canno 

 always be strictly applied, if we would not violate natural affinity 4 

 The normal number of the joints of the tarsus is in this order, as ii 

 most hexapod insects, five, and therefore by far the most of th 



1 Comp. DE HAAN, Memoires sur les metamorphoses des Coleopt&res. Nouvelh 

 Annalesdu Museum, IV. 1835, pp. 125 164, PI. 10 19. 

 3 Revue Entom. par SILBERMANN, i. 1833, p. 52. 



3 PH. W. J. MDLLER, Bemerkungeniib. die Fussgliederzakl einiger Kafergattungei 

 in ILLIGER'S Magaz. f. Ins. iv. 1805, s. 197 219. 



4 I communicated some remarks on this subject in OKEN'S Isis, 1824. s. 222, 223. 



