Ward — The Variations in Proportions in Bats. 639 
the ear and head. However, the lesser lengths dealt with in 
the case of the phalanges, rather than a greater diversity of 
measurements, accounts for this disparity in per cent, of varia¬ 
tion. The variation in relative as well as absolute length of 
the tail are considerable. This organ may be but 96^ the length 
of the head and body or it may be 124 per cent, of its length. 
There is an absolute difference of 12 mm. on bodies differing in 
length by only 1 mm., viz., Nos. 699 and 742, both males. Dob¬ 
son says: “Tail much longer than the head and body.” 
Comparing the forearm and second metacarpal we find in No. 
699 that a forearm of 36 mm. may bear a metacarpal of 41 mm., 
while in No. 695 a forearm of 40 mm. may have a metacarpal 
only 39 mm. in length, a reversal of proportions. 
The third, fourth and fifth metacarpals are about equal and in 
many cases measure the same, but either the third or fourth may 
be the longest or the shortest, while the fifth may be the shortest 
but never appears in these measurements as the longest. The 
proportions between the first and second phalanges of the third 
digit vary from 17:20 to 15 :23, those of the fourth digit from 
equal to 9 :11 and of the fifth digit from equal to 9 :12. 
The measurement of the second metacarpal of No. 747 is 
omitted because of its abnormality; measuring but 32 mm. in 
length and having joined to it, by a synovial joint, a phalanx 10 
mm. in length. Although the average length more nearly corre¬ 
sponds with Dobson’s “Var. a.” than with true stramineus yet 
in other points it agrees best with the latter. 
In the museum in T'acubaya were one or more specimens of 
this species collected in “southern Puebla.” 
Chilonycteris rubiginosa Wagner. 
Forty-one specimens collected near Jalapa, Veracruz, Feb¬ 
ruary 23, 1891, by H. L. Ward and O. M. Tehran. 
There is a considerably greater agreement in the graphs of 
length and of tail of this species than in either of the two species 
already examined; and the proportionate amount of variation is 
less than in them. The fifth metacarpal is usually the shortest 
but may equal the fourth. The third is usually the longest but 
may be equaled by the fourth. 
