530 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 95 
AMBYSTOMA SUBSALSUM Taylor 
Ambystoma subsalsum TayLor, Copeia, 1948a, No. 3, pp. 152-155 (Lake Alchi- 
chica, Puebla). 
Three paratypic larval specimens are in the collection, from Lake 
Alchichica, Puebla (U.S.N.M. Nos. 116702-116704). These were 
collected by Dyfrig McH. Forbes and the authors on March 21, August 
14 and 15, 1940. 
In life the larvae are golden-yellow and black-spotted. The yel- 
low color fades quickly when they are taken from the water. The 
adult has a greatly shortened tail, and is black and yellow spotted. 
AMBYSTOMA AMBLYCEPHALA Taylor 
Ambystoma amblycephala Taytor, Univ. Kansas Sci. Bull. vol. 26, No. 12, 1939 
(Nov. 27, 1940f), pp. 420-421, pl. 45, fig. 2 (15 km. west of Morelia 
[Tacicuaro], Michoacan). 
A series of 1387 larvae and transforming young were collected at 
Tacicuaro, Michoacin, the type locality, October 1, 1939; U.S.N.M. 
Nos. 116705-116720 have been cataloged. 
The larvae resemble somewhat those of Ambystoma velasci, and like 
them are not usually neotenic. They are, however, colored differ- 
ently. The length of the larvae above 60 mm. averages 66.3. Only 
eight reach 70 mm., the five largest being 72, 72, 75, 75, 77 mm. 
The length of the transforming young varies, and it is possible that a 
few larvae may become neotenic. The smallest transforming specimen 
measured 52 mm., the tail 41 mm.; average size of transforming young 
about 65mm., the tail 51.6 mm. The smallest transformed specimen 
measured 58 mm., tail 44 mm.; the largest 92 mm., tail 71 mm., which 
approximates the measurements of the type (90 mm. and 71 mm., for 
the same measurements). All these possess remnants of the gills. 
The dentition of the young larvae (50 mm., tail 41 mm.) follows: 
Vomerine teeth about 52-52, arranged in 8 rows, 3 to 15 teeth in each; 
pterygoid teeth 25-25, arranged rather irregularly, separated from 
the vomerine teeth; maxillary-premaxillary teeth about 36-236, 
rather irregular, perhaps two rows in front part of mouth; splenial 
teeth about 54-54, arranged in three or four long irregular rows; 
mandibular teeth 36-36. At this size the body is yellowish fawn, the 
dorsal and ventral caudal fins blackish. 
In a larva of 70 mm. the dentition is: (about) maxillary-premax- 
illary, 45-45; vomerine, 56-58; pterygoid, 438-43; splenial, 72-72; 
mandibular, 46-46. 
In the transforming specimens the pterygoid (palatine) series is 
oreatly reduced, as is also the vomerine series. In some only a few 
teeth remain. Many of the maxillary teeth are apparently lost 
and the entire splenial series is lost. It is presumed that the adult 
dentition is partially, if not wholly, acquired during or after trans- 
