288 
Indiana University Studies 
All of us have been confusing the galls of these several 
varieties of bella and dugesi for some years. Careful examina- 
tion of many galls of the two shows that some of them are 
more polished and shining than others, but there are so many 
of intermediate character that this fails to separate the spe- 
cies. Microscopic examination of the galls shows that some 
have a coriaceous surface and others have a smooth surface 
that bears fused irregularities ; there are few intergradations 
in this character, but thus far all the insects which we have 
definitely connected with galls (both of bella, and of the varie- 
ties dugesi, simulatrix, and brevipennata of the species dugesi) 
are connected with coriaceous galls. The opaqueness of the 
galls seems to depend upon a coriaceous surface in conjunction 
with a thick shell. The coriaceous surface is not necessarily 
correlated with a thick shell, and there are many grades of 
thickness and of luster evident in large series. 
Considering the many cases in Cynips of species and varie- 
ties that are almost unrecognizable except on gall characters, 
it is instructive to find Cynips dugesi and Cynips bella pro- 
ducing practically identical galls. 
The galls of these two species appear in the early summer. 
Mature galls with small larvae are obtainable late in August. 
The adults develop late in October or early in November, and 
emerge at various dates after that. Most of the adults have 
emerged by the end of November, but I found some normal 
emergence occurring at a number of localities in New Mexico 
late in December (1919) and in Arizona thruout the month 
of January (1920) under mid-winter conditions in the moun- 
tain ranges where the oaks and cynipids occur. Within a few 
hours after the galls are removed from the trees, their nor- 
mally pliable outer shells become hard and brittle, and then 
it seems difficult or impossible for the insects to cut into the 
concave surfaces with their jaws. This is a big factor in 
preventing normal emergence after collecting. With few ex- 
ceptions the hosts of these species are evergreen oaks to the 
leaves of which most of the galls remain attached over the 
winter; for part of this time the galls are kept soft by the 
wet snows of the mountains, but they are often exposed and 
perhaps dried out enough at many times to delay the normally 
earlier emergence. 
