■ THE GENUS DENDKOCTONUS. ' ' 77 



DIVISION II. 



Larval mines s,.parate, especially beyond the middle Subdivision C. 



Larval mines contiguous, forming broad larval chamber Subdivision D. 



Subdivision C. 



Egg galleries slightly winding to straight; eggs in groups, but larval mines separate 

 from the beginning Section a3. 



Egg galleries broad, nearly straight; eggs in small to large groups, the larval mines 

 usually contiguous toward the egg gallery Section a4. 



Section a3. 



Larval mines normally short and hroad Species 12. 



Larval mines normally long Species 13. 



Section a4. 



Subsection b3. 



Larval mines separated beyond the middle Species 14, 15, and 16. 



Subsection b4. 



Larval mines usually not separated beyond the middle, but forming a common chamber. 



Species 19 to 21. 

 Subdivision D. 



Egg galleries broad to very broad, short to very long, straight to winding; larval mines 

 forming a large common chamber. Species 22 and 23. 



TABLE OF DISTRIBUTION.a 

 America, north of Guatemala, and in northern Europe The genus. 



DIVISION I. 



Subdivision A. 



North American continent, in South Atlantic and Gulf States and Southwestern 

 States, southward to Guatemala and northward in Sierra Nevada and Cascade 

 Mountains to British Columbia .' Sections al and a2. 



Section al. 



West of western Montana and southwestern Idaho, and southward to Santa Barbara 

 County, California Species 1, page 81 . 



South of southern Colorado and Utah, into Texas and Mexico, and westward into 

 southern California, and possibly in the Coast Range and northward along the 

 forested foothills into northern California Species 2, page 85. 



Section a2. 



Southern Colorado and Utah, southward into Mexico Species 3, page 87. 



Atlantic and Gulf States, south westward into Texas Species 4, page 90. 



Central to southern Arizona , Species 5, page 95. 



Southern Mexico Species 6 and 7, pages 97, 99. 



Central Colorado and southern Utah, southward to southern Arizona, and New Mexico. 



Species 8, page 101. 



o For exact and probable distribution see maps under description of each species. 



