MEXICAN AMPHIBIANS—TAYLOR AND SMITH 527 
RHYACOSIREDON LEORAE Taylor 
Rhyacosiredon leorae 'TAYLoR, Univ. Kansas Sci. Bull., vol. 29, pt. 2, 1943b, pp. 
345-347, pl. 26, fig. 3 (type locality, mountain stream near Rfo Frio, México, 
in the state of Puebla almost on the border between the two states). 
Four paratype specimens are in the collection (U.S.N.M. Nos. 
116629-116632). These were obtained by Dyfrig McHattie Forbes 
at the type locality on October 7, 1939. 
The adults are extremely shy, hiding under the cut-in edges of the 
stream at the least disturbance. We visited this stream several 
times, but its turbulent condition prevented our securing further speci- 
mens. 
RHYACOSIREDON RIVULARIS Taylor 
Rhyacosiredon rivularis Taytor, Herpetologica, vol. 1, No. 7, Jan. 29, 1940a, 
pp. 171-176, pl. 17, fig. 1 (13 km. west of Villa Victoria, México). 
Two specimens were obtained at the exact type locality (U.S.N.M. 
Nos. 116595, 116596) about 13 km. west of Villa Victoria in the re- 
cently established Bosencheve National Forest (Kilometer 129), on 
September 11,1939. They agree with the type in all essential details. 
RHYACOSIREDON ZEMPOALAENSIS, new species 
Type—U.S.N.M. No. 116617, adult larva, collected at the Lakes 
of Zempoala, Morelos, México, in a nearly dry lake bed, elevation 
about 10,000 feet, February 24, 1939, by Hobart M. Smith. 
Paratypes—U.S.N.M. Nos. 116614-116616, 116618-116628, Feb- 
ruary 21-24, 1939, H. M. Smith, collector; E.H.T.—H.M.S. Nos. 
22172-22190, August 25, 1939, 24680-24634, June 18, 1940, E. H. 
Taylor and Richard C. Taylor, collectors. 
Diagnosis—Somewhat similar to Rhyacosiredon altamirant but 
with slenderer limbs and digits and a somewhat more elongate body; 
the hindleg brought forward, the toes fail to reach the elbow by about 
one to three costal folds; the head is slenderer and the tailis much shorter 
than head and body. The adult is purplish slate to gray-slate above, 
with chin dark and light; abdomen purplish; the lips, tips of fingers, 
and narrow subcaudal fin are whitish. 
Description of type-—Head elongate, rather slender, moderately 
elevated, the length 19 mm., the greatest width 15 mm.; from tip of 
snout to nuchal fold, 15 mm.; gills very short, the basal portion about 
2.5 mm. long; width between nostrils about equal to the interorbital 
distance; eye small, its length about two-thirds the distance to nostril; 
mouth very narrow, the labial fold visible, the upper lip somewhat 
notched behind the fold; neck fold free for 8 mm. on median longitu- 
dinal line, notched medially. , 
Maxillary-premaxillary series of teeth 20-20, counting absent 
teeth; the series reaches back to near the anterior level of choanae; 
