246, September, type from Bogava [= Bugaba], Chiriqui,
250 meters, Panama.

1960. _Lasiurus ega panamensis_, Handley, Proc. U.S. Nat. Mus.,
112:474, October 6.

_Geographic distribution._--Panama; also recorded by Handley
(1960:474) from Venezuela.

_Diagnosis._--"General colour dark brownish clay-color, something
between Ridgway's 'raw-umber' and 'clay-color'. Fur black basally,
then dull brownish buffy, the extreme tips black. Center of face
similar to back, cheeks from eyes to lips contrasting black. Rump
and hairy part of interfemoral verging toward brownish fulvous.
Under surface similar to upper." (Thomas, 1901:246.) Forearm of
holotype, 46.5.

_Remarks._--Notes taken down by one of us (Hall) on July 16, 1958,
at the British Museum, Natural History, contain the following:
"Color accurately described by Thomas. The blackish stands out. The
difference between the types of _D. e. panamensis_ and _D. e.
xanthinus_ is tremendous."

_Record of occurrence._--Specimen examined, one, the type (British
Mus.).

RELATIONS BETWEEN THE SPECIES OF LASIURUS

As suggested by Dalquest in 1953 (p. 62) and by Handley in 1959 (p.
119) and 1960 (p. 473), the yellow bats, _Lasiurus ega_ (Gervais) and
_Lasiurus intermedius_ H. Allen, so closely resemble the hoary bat,
_Lasiurus cinereus_ (Palisot de Beauvois), and the red bats, _Lasiurus
borealis_ (Mueller) and the seven related species listed below, that
all are properly included in a single genus. Many of the common
characteristics are enumerated above in the diagnosis of the genus
(see also Handley, 1960:473).

[Illustration: FIG. 3. Diagram of bones of right arm and third finger
(middle digit) including cartilage on distal end of terminal (3rd)
phalanx. Percentages are in terms of the over-all length of the arm and
third finger.]

A listing of the differences between the species is less impressive
than a listing of the resemblances. The yellow bats differ less from
the red bats than does the hoary bat, _L. cinereus_, which differs from
all of the others as follows: talonid on m3 larger; p4 single-rooted
instead of double-rooted; hypocone on M1 and M2 smaller; coronoid
process lower; ossified part of tympanic ring, which shields the
petrosal, larger; humerus relatively shorter; forearm relatively
longer; first phalanx of middle finger relatively shorter; presternum
including keel longer th