14 THE SCOLYTID BEETLES. 
In species 12 and 13 the egg galleries are long, longitudinal, straight, 
or slightly winding, sometimes branched, and moderately broad; the 
larval mines are long, independent of each other from the start, 
winding, and more or less regular. 
In species 14 to 21, so far as observed, t-he egg galleries are broad, 
moderately long, straight, irregularly branched at terminals, and 
usually with an inner gallery through the packed borings of the 
finished egg galleries; the larval mines are long, connected toward 
the egg gallery, independent and irregular, or forming a broad larval 
chamber. 
In species 14, 15, and 17 the larval mines are connected toward 
the egg gallery and separated toward the middle and outer ends. 
In species 19 and 20 the larvse excavate a common or social cham- 
ber, sometimes with independent mines extending from the edges. 
In species 22 and 23 the egg galleries are broad to very broad, 
short to very long, and straight or slightly winding, and the larval 
mines form very large common chambers, with the pupal cells in the 
chamber or at the ends of short independent mines extending from 
the edge of the chamber. 
DISTRIBUTION. 
The distribution of the species of Division I is from the South 
Atlantic States to Mexico and Central America, and northward into 
the Rocky, Sierra Xevada, and Cascade mountains to British 
Columbia. 
Species 1 occupies the region of the western yellow pine west of 
western Montana and southern Idaho, southward to Santa Barbara 
County, Cal., while species 2 occupies the Rocky Mountains region 
south of central Colorado and central Utah, into southern California 
and northern Mexico. 
Species 3, 5, and 8 occupy practically the same region as species 2, 
while species 4 occupies the region of yellow pine, loblolly pine, and 
longleaf pine south of Pennsylvania and westward into Texas, and 
species 6 and 7 occupy the pine regions of the mountains of southern 
Mexico. 
Species 9 occupies the region of silver pine, lodgepole pine, and 
sugar pine north of Colorado and Utah and westward into the Sierra 
Xevada and Cascade mountains. 
Species 10 occupies the region of the Rocky Mountain variety of 
the western yellow pine and limber pine above an altitude of 6,000 
feet, from western South Dakota southward through Wyoming, 
Colorado, and Utah to southern Xew Mexico and Arizona, while 
species 11 occupies the Jeffrey-pine region from the mountains of 
San Bernardino County, Cal., to northern California, and probably 
into Oregon. 
