HOWELL — CALIFORNIA BAT ROOSTS 
169 
It is possible that others of the smaller species of Paramys would 
prove to belong to this genus, if better known. P. copei Loomis of 
the Wind River (Plesiarctomys delicatissimus of Cope) certainly does 
not. 
The relations of this genus are clearly with Paramys and not with 
Mysops or Sciuravus, but it presents an interesting new variant on the 
very limited range of structural divergence found among Eocene rodents. 
The characters of the infraorbital region are as in Paramys, except 
that the muscle scar on the inferior surface of the root of the zygoma 
is less sharply marked off from the anterior surface, which is pitched 
so as to face more downward, and lacks the pit that in P. delicatus in- 
tervenes between the infra-orbital foramen and the first upper premolar 
p.^ The latter tooth is also smaller than in P. delicatus. These are 
individually variable characters in P. delicatus, and are not of generic 
importance. 
SOME CALIFORNIAN EXPERIENCES WITH BAT ROOSTS 
By a. Brazier Howell 
[Plate 9] 
To those who have investigated bats and their habits to even a slight 
extent, these mammals are of particular interest. From earliest times 
they have been so little known and understood that they have been 
regarded with greatest superstition. They hunt during the hours of 
darkness, spend the day in hiding in out-of-the-way places, and are 
altogether such retiring, elusive little beasts, that the mammalogist 
who would become better acquainted with them must be continually 
on the alert. While riding about the country, one should keep an eye 
subconsciously active to remark favorable locations, such as large 
attics with slatted ventilators. If a colony has taken possession of the 
space between the walls of a house or cornice, there will often be a tell- 
tale smudge made by the rubbing of small bodies as they emerge from 
hiding. While fortified with a pocket full of cigars, a collector, by 
judicious questioning of village constables, blacksmiths, and such public 
characters will often meet with success; and I have obtained excellent 
results from advertising in farm papers. 
Our bats may be placed for convenience in two arbitrary groups — 
those which roost singly or a very few together in trees, high cliffs, 
or similar locations; and those which are in the habit of gathering in 
