COLEOPTERA. 409 



and sometimes consisting of three elongated leaflets; and at others 

 forming a cylindrical and perfoliate club from their base, and in 

 which the palpi are conical. The anterior legs of the greater num- 

 ber are dentated and armed with a stout hook, and the tarsi, of 

 which the penultimate joint is frequently cordiform or bilobate, are 

 susceptible of being flexed on them. 



Some have very small palpi, the body convex and rounded above, or al- 

 most ovoid, the head globular and plunged into the thorax, and the antennx 

 soUd or trilamellate, and preceded by five johits at least. 



These Xylophagi form the genus 



ScoLYTTJs, Geoff. 



In Scolytus properly so called, the antennae are straight, beardless, and in- 

 serted close to the inner margin of the eyes, which are narrow, elongated, 

 and vertical. 



The others have large and very apparent palpi of unequal lengths. 

 Their body is depressed and narrowed before; their antennae sometimes 

 consist of two joints, the last of which is very large, flattened, and almost 

 triangular or nearly ovoid, and sometimes of ten, and are entirely perfoliate. 



The labium is large; the elytra are truncated, and tarsi short, with all the 

 joints entire. These insects are all foreign to Europe, and compose the 

 genus 



Paussus, Lin. 



Where the antennx consist of but two joints, with the last large and com- 

 pressed. 



2. A second section will comprise those Xylophagi, whose an- 

 tennae consist of but ten joints, and in which the palpi, at least those 

 of the maxillae, do not gradually taper to a point, but are of equal 

 thickness throughout, or dilated at the extremity. The joints of 

 their tarsi are always entire. 



We will divide them into principal genera, according to the mode 

 in which the antennae terminate. The three last joints form a per- 

 foliate club in the flrst, or 



BOSTRICHUS. 



In Bostrichus proper, the body is more or less cylindrical, the head round- 

 ed, almost globular, and capable of being received into the thorax as far 

 as the eyes; the thorax is more or less convex before, and forms a sort of 

 hood; the two first joints of the tarsi, as well as the last, are elongated. 

 3 B 



