THE WRINKLED BARK BEETLES. 



559 



KEY TO GENERA OF RHYSSODIDiE. 



a. Elytra not grooved, but with distinct rows of punctures. 



I. Rhyssodes. 



aa. Elytra deeply grooved, without punctures. II. Clinidium. 



I. Rhyssodes Dalman. 1825. (Or., "wrinkled + form.") 



In this genus the thorax has three deep, entire grooves and one 

 finer line on each side. The eyes are rounded, distinctly granu- 

 lated and situated on the sides of the head; the middle and hind 

 tibiae have one terminal spur. 



*1067 (3295). Rhyssodes americanus Lap., Silberm. Rev., IV, 1836, 58. 



Elongate, narrow. Uniform dark reddish-brown, shin- 

 ing. Thorax one-half longer than wide, broadly rounded on 

 the sides; furrows very deep, the two outer ones dilated be- 

 hind. Elytral strise composed of large punctures, the inner 

 ones rather deeply impressed. Front femora of male armed 

 with a distinct tooth. Length 6-7.5 mm. (Fig. 209.) 



Frequent throughout the southern half of the 

 State ; less so in the northern counties. April 14-De- 

 cember 18. Both this species and the next hibernate 

 singly or in small colonies beneath the close fitting 



& • Fig. 209. X 4J. 



bark of beech, oak and elm logs, rarely beneath mul- (Original.) 

 lein leaves. One of these colonies containing 18 specimens was 

 noted on November 28, beneath the bark of an elm log. This is the 

 species usually called exaratus Serv., which name was preoccupied. 



II. Clinidium Kirby. 1829. (Gr., "a slope + little.") 



In addition to the deeply grooved elytra devoid of punctures, 

 this genus may be known by the thorax having one entire dorsal 

 line, two short, deep basal impressions and a double line on each 

 side ; eyes narrow, scarcely granulated, confined to the upper side 

 of the head ; middle and hind tibiae, with two terminal spurs. 



*1068 (3297). Clinidium sculptile Newm., Nat. Hist., 1838, 666. 



Form and color as in R. americanus. Thorax oblong, nearly twice as 

 long as wide, sides broadly rounded. Elytra with the intervals narrower 

 than the deep intervening grooves. Front thighs of male distinctly toothed. 

 Length 5.5-7.5 mm. 



Throughout the State; frequent. February 21-November 8 

 Mating on April 9. 

 [ 36— 23402] 



