432 THE AMERICAN NATURALIST. [Vor. XXXV. 
for the sake of comparison, to follow it with a consideration of 
the other forms of mixed and compound nests that are known to 
occur on our continent. While it thus becomes necessary to 
review much that is well known to the myrmecologist, I hope at 
the same time to call the attention of entomologists, who may 
have wearied of collecting and mounting our comparatively well- 
known beetles and butterflies, to an extensive subject, which is 
as interesting to the collector as it is fascinating to the philo- 
sophical observer. Ants’ nests of the mixed and compound 
varieties are of sporadic and often very rare occurrence, so that 
there is great need of many more observations extending over 
large portions of our country. While reviewing the various 
forms of nests in the second part of my paper, I shall include a 
brief consideration of some interesting compound nests that have 
recently come under my observation in Texas and Mexico. 
During the late afternoon of August 1, 1900, while walking 
over one of the Litchfield Hills near Colebrook, Connecticut, 
I found a number of nests of the common red-brown Myrmica 
(M. brevinodis Emery) under some small stones that were 
rather deeply imbedded in the moss bordering the exposed gla- 
ciated rock of the hilltop. In four of these nests which were 
rather close together and not very populous I detected among 
the Myrmica workers a few decidedly smaller and more yellowish 
ants of a different species running about on the up-turned lower 
surfaceof thestones. As my stay in Colebrook was at that time 
limited to a few days, I carefully replaced the stones in the 
moss after preserving a few of each of the two species. The. 
smaller ants were sent to Professor Emery of Bologna, who pro- 
nounced them to be a new species of Leptothorax allied to 
L. canadensis Provencher. 
Later in the month of August I returned to Colebrook and 
at once revisited the Myrmica-Leptothorax nests. ae of 
them had disappeared, as if in resentment of my former intru- 
sion into their peaceful life on the hilltop. The third nest a 
tained only a few Leptothorax workers. The fourth nest was 1n 
good condition and was dug up zz £oze and carried home in xu 
vas bag. For several days I searched diligently, but in vain, m 
all the hills about Colebrook for more of these double nests, 
