96- INSECTA. 



Synchita, Hellw., Dej. — Lyctus, Elophorus, Fab. 



AVhere the anterior extremity of the head is transverse and with- 

 out any prolongation, where the two first joints of the antennae are 

 almost identical, and where the thorax, much wider than it is long, is 

 separated from tlie base of the elytra by an evident interval *. 



Cerlyon, Lat. — Synchita, Hellw. — Lyctus, Fab. 



Where the anterior extremity of the head projects in the manner 

 of an obtuse triangle; the first joint of the antennae is much larger 

 than the second ; the thorax is applied posteriorly to the base of the 

 elytra, is wider than it is long, or almost isometrical, and without 

 any recui-vature of the margin. The body is almost oval or nearly 

 forms a parallelopiped, and the elytra are truncated posteriorly and 

 cover the whole top of the abdomen f. 



Rhyzophagus, Herbst., Gill. — Lyctus, Fab. 



Resembling the preceding in the head, the relative dimensions of 

 the first joints of the antennae, and the junction of the thorax with 

 the abdomen ; but the body is narrow and elongated, the thorax 

 wider than long, with a recurved margin ; the elytra are truncated 

 posteriorly. Some authors have asserted, that by their tarsi they 

 are heteromerous — I rather think they prove them to be' penta- 

 merous +. 



The others, 



MoNOTOMA, Herbst. — Cerylon, Gyll., 



Or Monotoma properly so called, have a head of the same width as 

 the thorax, and sepanaed from it by a strangulation. 



The two first joints of the antennae are stouter than the folloAving 

 ones, and almost equal — the first a little larger. The superior extre- 

 mity of the club, or button, seems to present vestiges of one or two 

 joints. The head is triangular, and somewhat extended into an ob- 

 tuse snout. The bodv is elongated, and the thorax longer than it is 

 wide §. 



3. The Xylophagi of the third division have eleven very distinct 

 joints in the antennae ; their palpi are filiform, or thicker at the extre- 

 mity in some, and smaller in others ; all the joints of the tarsi are 

 entire. 



We will begin with those in which the club of the antennse con- 

 sists of but two joints. They form the genus 



Lyctus. 



In some, the mandibles and first joint of the antennae are com- 



* Cerylon terebrans, Lat. ; C. juglandis, Gyll. ; Lyctus juglandis, Fab. ; Elophorus 

 humeralis, Ejusd. 



f Cerylon histeroides, Lat., Gylleuhall. 

 X See Gyll., Insect. Suec, I, iii, p. 419. 

 § Cerylon picipes, Gyllenhall. 



