Taxonomic Notes on Mexican Bats of the

Genus Rhogeëssa

BY

E. RAYMOND HALL

University of Kansas Publications

Museum of Natural History


Volume 5, No. 15, pp. 227-232

April 10, 1952

University of Kansas

LAWRENCE

1952

University of Kansas Publications, Museum of Natural History


Editors: E. Raymond Hall, Chairman, A. Byron Leonard,

Edward H. Taylor, Robert W. Wilson


Volume 5, No. 15, pp. 227-232

April 10, 1952

University of Kansas

Lawrence, Kansas

PRINTED BY

FERD VOILAND, JR., STATE PRINTER

TOPEKA, KANSAS

1952



24-1780

Taxonomic Notes on Mexican Bats of the

Genus Rhogeëssa

BY

E. RAYMOND HALL

Five skins with skulls of Rhogeëssa, collected by J. R. Alcorn in the
states of Sonora and Nayarit of western Mexico, were recently received
at the Museum of Natural History of the University of Kansas. Two other
specimens of the same genus, collected by Walter W. Dalquest in the
state of Veracruz of eastern Mexico, also are in the Museum of Natural
History. With the aim of applying names to these bats they were compared
with materials in the United States National Museum (including the
Biological Surveys collection) where there are approximately the same
number of Mexican specimens of Rhogeëssa as are in the Museum of
Natural History.

The three kinds of Rhogeëssa named from Mexico are as follows: R.
parvula from the Tres Marias Islands off the west coast of Nayarit; R.
tumida from Mirador, Veracruz, on the eastern slope of the Republic;
and R. gracilis from Piaxtla, Puebla, on the southern end of the
Mexican Plateau.

Of Rhogeëssa gracilis Miller (N. Amer. Fauna, 13:126, October 16,
1897) only three specimens are known; two are from Piaxtla, Puebla, and
the third is from the Isthmus of Tehuantepec. Only the specimen from the
Isthmus has a complete skull. The broken skull of the holotype is partly
separated from the skin of the head and in such a manner as to reveal
the teeth. The skull of the holotype seems to be broader (relative to
its length) across the mastoids and posterior parts of the zygomata than
in R. tumida or than in R. parvula. My comparisons indicate that
Rhogeëssa gracilis has larger (longer and wider) ears than R.
parvula and R. tumida and that it is specifically distinct from the
two last mentioned kinds.

The two other nominal species from Mexico, R. parvula and R. tumida,
were named and described by Harrison Allen (Proc. Acad. Nat. Sci.
Philadelphia, 1866: 285 and 286, respectively) on the basis of three
specimens in the United States National Museum. Two were from the Tres
Marias Islands and were the basis of the name R. parvula; the third
was from Mirador, Veracruz, and was the basis[Pg 230] of the name R. tumida.
These specimens seem to have been preserved in alcohol. I have examined
the skulls of two of these. One (U.S.N.M., new number 37329, old number
7842) is alleged to be the paratype of R. parvula and the other
(U.S.N.M., 84021) is alleged to be the holotype of R. tumida. In the
glass vial containing skull No. 84021, there is a label in the
handwriting of Gerrit S. Miller, Jr., bearing the following information:
"In the orig. descr. the number of this sp. is said to be 8195. This is
an error. Specimen catalogued 3.1.98 G.S.M. Jr." On the back of a second
label in the skull vial there is written, "There is no doubt that this
is the type skull. It was returned by H. A. with no. given in orig.
descr. G.S.M. Jr." In the catalogue of the U. S. National Museum there
is the statement that the type of Rhogeëssa tumida was collected by H.
A. Grayson.

The name Rhogeëssa parvula was based on two specimens (Smithsonian
Institution Nos. 7841 the type and 7842, in alcohol, collected by Col.
Grayson in the Tres Marias Islands off the west coast of Mexico.) The
type seems never to have been returned from the Academy of Sciences of
Philadelphia to the U. S. National Museum in Washington, D. C., and
cannot (in 1951) be found in Philadelphia or anywhere else. The skull,
but no other part, of the second specimen is in the United States
National Museum under the catalogue number 37329 (old No. 7842). The
skull has been broken in two through the interorbital region but is
glued together.

Of R. tumida, no additional specimen has been saved, so far as I know,
from the type locality, Mirador, Veracruz.

Of R. parvula, Nelson and Goldman, on May 19, 1897, on María Madre
Island, saved in alcohol an additional specimen (92413 U.S.N.M.) from
which J. Biggs, Preparator at the National Museum, in 1951, removed and
cleaned the skull. In small size and in all other features, the skull of
92413 closely resembles those of specimens saved by Alcorn from the
adjoining mainland of Mexico in Sonora and Nayarit. The pelage of the
upper parts of 92413 could be described as "of a light greyish-brown at
basal third, fawn-chestnut-brown at apical two-thirds" which are the
words that H. Allen (op. cit.: 285) used to describe the pelage of his
R. parvula. The external measurements of 92413 are: total length, 60;
length of tail, 25; length of hind foot, 5.5; and ear from notch, 11.0.
The first two measurements are slightly smaller than the corresponding
measurements of any other specimen seen. Nevertheless, the measurements
(tail, 30.5; hind foot, 5.3 [after H. Allen, orig. descr.]) of the[Pg 231]
holotype of R. parvula, also from the Tres Marias Islands, show that
it was as large as no. 39724 from the adjoining mainland (see table 1).

According to the original descriptions, R. parvula and R. tumida
differ in size, R. parvula being the smaller. As may be seen from
table 1, the alleged type of R. tumida and the alleged paratype of R.
parvula indicate the opposite! All specimens obtained since the time of
the original descriptions, as may be seen by inspecting table 1, support
the correctness of the original descriptions. Therefore, and also
because of the other information presented above, I am inclined to the
opinion that the holotype of R. tumida and the paratype of R.
parvula have been switched; each now is associated with the name and
data, at least for locality, of the other.

Other opinions are that Rhogeëssa from the Tres Marias Islands average
smaller than Rhogeëssa of the adjoining mainland of western Mexico but
not enough smaller to warrant subspecific separation of the two.
Specimens from places geographically intermediate between the geographic
ranges, as now known, of R. parvula and R. tumida probably will
reveal intergradation between the two kinds, which, therefore, should
stand as subspecies of a single species.

As understood now, the Mexican Rhogeëssa are as follows:

Transmitted November 30, 1951.

TABLE LEGEND

Column FO: Forearm

Column GR: Greatest length of skull including teeth

Column CO: Condylobasal length (not including teeth)

Column LE: Length of upper tooth-row, C1-M3

Column ZY: Zygomatic breadth

Column MA: Mastoid breadth

Column BR: Breadth across upper molars

Transcriber's Notes:

Standardized Punctuation.

Left inconsistent usage of accents.

Page 229: Changed Ishtmus to Isthmus.

Footnote A: Changed Natoinal to National