906 The American Naturalist. [October, 
bushes (Larrea mexicana), on the mesa to the east of Las Cruces, New 
Mexico. All the galls of this species that have been found, however, 
have invariably been dried and dead ones. No green ones have been 
met with. The following description is drawn from old galls. 
Gall.—Diameter, 18 to 27 mm. Rounded, more or less spherical in 
general shape, always formed around the twig which usually represents 
the axis of the gall; consisting of a rather hard central portion formed 
of resinous closely packed layers of very narrow leaflets radiating in 
all directions from the central point outward. The larvee of the gall- 
maker live and transform in rather closely approximated cells on all 
sides, in this portion, with their ends all pointed to the center. Out- 
side of this cell-containing portion, the very narrow leaflets, which 
nearer the center are closely packed into a resinous and nearly solid 
mass, are prolonged each one separately but more or less disposed in 
whorls, thickly covering the whole outer surface of the gall. These 
give the gall a coarsely fibrous appearance, as if it consisted of a knot- 
ted bunch of coarse fibers with the ends all sticking outward on the 
surface. The color of the dried galls is brown, varying from light to 
dark ; that of the growing gall is doubtless green. The cells above 
mentioned, in which the gall occupants live, are rather elongate, 
pointed at the inner end, slightly flattened, about 14 mm. in greatest 
width one way by 1} mm. the other, and about 4 mm. long. 
Described from three galls collected May 15, 1891. They are with 
hardly any doubt hymenopterous. Galls contain no remains of occu- 
pants. In plan of structure this gall greatly resembles that formed by 
a species of Andricus on leaves of scrub oak in the Organ Mountains. 
(See Can. Ent., 1892, p. 200). 
—C. H. TYLER TOWNSEND, 
