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MEXICAN AMPHIBIANS—TAYLOR AND SMITH 529 
female has a distinctly mottled tail. Several specimens show abnor- 
malities in the digits. 
Remarks.—We cannot be certain, but we presume that at least a 
part of the neotenic population transforms since the three other known 
forms do. However, in the collections of the other forms secured at 
the same time of the year, transformed specimens are perhaps more 
frequently found than the larvae, yet none are present in our series 
of zempoalaensis. In the entire material before us, 37 specimens, 
there are several sexually mature specimens as attested by the greatly 
inflated cloacal region in the males, and the presence of large pigmented 
ovarian eggs in the females. It is, of course, possible that the adults 
are more terrestrial, although the three other species ordinarily re- 
main in the water after transforming. However, two recently trans- 
formed specimens of Rhyacosiredon altamirani were found on land 
under small logs lying partly in water and partly out of the water. 
The salamanders were only a distance of inches from the water. 
The type locality is a spring at the bottom of an old lake, and ex- 
cept for a very small bog area the bottom is a meadow. The spring 
forms a sluggish stream about 40 feet long, which disappears under 
some rocks. It seems likely that this species could easily have access 
to other waters by means of underground connections, regardless of 
whether they transform and migrate overland. 
We do not overlook the possibility that this larval form may not 
belong to the genus to which we have assigned it, since the “‘ generic” 
character is to be ascertained only after the loss of the gills. 
Although Rhyacosiredon altamirant occurs in streams not over 
a quarter of a mile away, we found none in the lake bed occupied 
by zempoalaensis. The habitats of the two are strikingly different. 
Genus AMBYSTOMA Tschudi, 1838 
AMBYSTOMA ORDINARIA Taylor 
Ambystoma ordinaria TayuLor, Univ. Kansas Sci. Bull., vol. 26, No. 12, 1939 
(Nov. 27, 1940f), pp. 422-424 (4 miles west of El Mirador, near Puerto Hon- 
do, Michoac4n). 
A series of 41 topotypic larvae comes from the exact type locality, 
collected September 12, 1939. U.S.N.M. Nos. 116721-116735 have 
been cataloged. These agree with the type series completely. 
This species is at least partially neotenic. Certain of the larval 
males have the cloacal region inflated equally as much as transformed 
males, while some larval females contained large pigmented ovarian 
eggs. 
Live specimens placed in alcohol exude a very large quantity of 
mucus, which forms a thick, fibrous, cheeselike substance. It was 
especially noticeable on the under surface of the hands and the feet 
and on the tip of the snout. 
