PKELIMINAKY CLASSIFICATION" OF SCOLYTOIDEA. 



171 



antennae (145); eyes (143), epistoma (6), front of head (2) — total 

 for head including antennae (297); pronotum (29), elytra (12), tarsi 

 (8), tibia (6), form of body (5), pygidium (2), abdominal sternites (2), 

 and coxae (5). Thus it is shown that the most important generic 

 characters are found in the antennae and eyes. 



A summary of the principal character-bearing parts, as recognized 

 by the writer in his preliminary classification, may be tabulated as 

 follows : 



Table I. — Summary of principal character-bearing parts in the super/amily Scolytoidea. 



Characters. 



In the su- 

 perfamil5^ 



In the 

 families. 



In the sub- 

 families. 



In the sub- 

 sections 



and series 

 to the 

 genera. 



Tarsi, first joint 



Tibia, apical angles 



Head 



Pronotum 



Elytra 



Third tarsal joint 



Coxae 



Seventh abdominal sternite. 

 Pygidium 



Timesused. 

 2 

 3 



Timesused. 



Timesused. 



Timesused. 



6 

 297 

 29 

 12 

 8 

 5 

 2 



GENERIC CHARACTERS. 



The Antenna. 



(Fig. 96; Pis. X-XII.) 



antennal funicle. 



The antennal funicle is perhaps the most important taxonomic 

 element of the scolytoid beetles. It is one of the first things to be 

 looked for as a guide to the combination of characters which distin- 

 guish the genus and, at the same time, indicate its position in the 

 classification. While the same number of joints may be paralleled 

 many times in the genera of the same subfamily and in different sub- 

 families, the writer holds that, with very few exceptions, there must 

 be the same number of joints in the funicle of all of the species of a 

 genus. The exceptions are found in Hypothenemus and Stephano- 

 deres, in which the males are smaller than the females and the an- 

 tennal funicle has a less number of joints. The males m Xyleborus 

 and allied genera are also smaller than the females, but usually have 

 the same number of joints. Occasionally there is a smaller number 

 or other abnormal developments. (See fig. 97.) 



The writer's conclusions are based on the study of balsam mounts 

 of representatives of all of the genera which have been available to 

 him, and of a large percentage of the commoner species. It has 

 been found that a normal variation in the number of joints in the 



