32 W. G. DIETZ, M. D. 



size, this species might readily be taken for frontalis, with which it 

 agrees in the large head, form of epistoma and structure of antennal 

 club, but easily distinguished by the greater length of second joint 

 of funicle and greater length and more conspicuous hairs. The 

 thoracic punctures are also a trifle coarser than in that species. 



D. frontalis Zimm., D. brevicoriiis Lee, Proc Amer. Philos. Soc. xv, 

 386. 



After careful examination of typical specimens of each, no 



doubt of their identity is left in my 



mind. The structure of the epistoma 



and the antennie is alike. In some 



% % the very short hairs on the elytra 



jii, , ' — 1^ are intermixed with a few, scattered, 



/^>^ x^''\^ a longer ones. With the exception of 



\ two specimens from New Mexico and 



California the front is channeled in all ; the frontal tubercles are 



variable in development. The sutures of the club are curved. 



Length 2.75 — 4.0 mm. ; .11 — .16 inch. 



California, Arizona, Maryland. 



Easily recognized by its small size. The resemblance to approxi- 

 matus has been referred to under that species. 



In conclusion I desire to call the attention of collectors to the 

 necessity of collecting observations and data in the life-history of 

 the ScolytidiE. Especially as to the time of their appearance, and 

 to the collecting of specimens of bark demonstrating the larval 

 passages from the time the larva leaves the ovum until it reaches 

 the pupal stage. The necessity of this will be evident to all who 

 coutemplate the future of our North American forests. 



