THE GENUS DENDROCTONUS. 



15 



the epicranium. It is represented by a frontal area, however, which 

 not only in this genus but in other scolytids presents characters of 

 special value in distinguishing major and minor divisions, species, 

 sexes, etc. The significance of frontal characters in this genus is 

 defined m the synopses of adult and secondary sexual characters 

 and shown in the figures. 



AntennsR (figs. 1-6, 11-13). — The characters of the antennae are 

 clearly shown in the figures. The scape, funiculus, and club are 



Fig. 7. — Pterostichus californicus: Head, dorsal and ventral aspects, and maxillse. A, Ventral aspect; B, 

 dorsal aspect; C, dorsal aspect of left maxilla; B, lateral aspect of left maxilla; E, ventral aspect of left 

 maxilla; a, stipal foramen; 6, muscle processes; c, lacinial digitus; d, cardo fossa; e, basal membrane; 



/, palpiferal bristle; g, stipal bristle; h, median fossa of ventral articulation of mandible; i, labral bristles; 



7, clypeal bristles. (Original.) 



nearly equal in length. The scape toward the apex is clavate — cy- 

 lindrical to angular. The funiculus is 5-jointed and always slightly 

 longer than the club. The first joint (or pedicel of some authors) is 

 of the usual form and as long or longer, rarely shorter, than the 

 second. The second joint is as long as the third, fourth, and fifth 

 together, or slightly shorter in some species, and the second to fifth 

 increase in width toward the club, which is broad, thickened toward 

 the base and compressed toward the apex, and has three or four 

 distinct segments, with two or three slightly to strongly curved 



