384 INSECTA. 



tarsi being always free, and the tibia? elongated and narrow, form 

 our seventh tribe, that of the DERMESTINI, and the great genus 



DERMESTES. 



In Dermestes, properly so called, the antennae are similar, or differ but very 

 slightly in both sexes; the length of the last joint is never much greater 

 than that of the preceding ones. 



Certain species do great injury among furs, and devastate our collections 

 of natural history. De Geer calls them dissectors, and in fact the Dermestes 

 lardarius cuts to pieces the Insects of the cabinet into which it has pene- 

 trated. The others devour the dead bodies of all kinds of animals. 



D. lardarius, L. Black; base of the elytra cinereous and dotted with 

 black. The larva is elongated, insensibly tapered from head to tail, of a 

 chesnut-brown above, white beneath, furnished with long hairs and two 

 squamous horns on the last annulus. 



There are various other Dermestini arranged in different genera, such as- 

 Jlttagenus, Megatoma, Jlnthrenus, Sec. 



The eighth tribe, that of the BYRKHII, differs from the preceding 

 in the perfect contractility of the legs; the tibiae are susceptible of 

 being flexed on the thighs, and the tarsi on the tibiae, so that when 

 thus folded and pressed against the body, the animal seems to be 

 inanimate and entirely destitute of feet. The tibiae are usually 

 broad and compressed. The body is short and convex. 



This tribe is chiefly composed of the genus 



BYRRHUS, Lin. 



The mentum of the true Byrrhii is of an ordinary size and interlocked (at 

 least partially) by the prasternum, whose anterior extremity is dilated. 



In some, the antenna enlarge insensibly, or terminate in an elongated 

 club formed of from five to six joints. 



S. pilula, L. From three to four lines in length? black beneath, black- 

 ish-bronze or soot-colour and silky above, with little black spots mingled 

 with lighter ones arranged in lines. 



All the Byrrhii remain on the ground in sandy localities. 



It is impossible to describe the Clavicornes of our second section, 

 although a very natural one, but by the reunion of several characters. 



The body of these Insects is generally ovoid, and their head 

 plunged to the eyes in a trapezoidal thorax, with a recurved lateral 

 margin, and terminating posteriorly in acute angles; the praester- 

 num is dilated anteriorly and the legs are imperfectly contractile. 

 They are found in the water, under stones in the vicinity of shores, 



