In tadpoles having fully developed mouthparts the tooth-row formula of 2/3 is invariable, but the coloration is highly variable. The color and pattern described above is about average. Some tadpoles are much darker, such as those from 11 kilometers north of Vista Hermosa, Oaxaca, (KU 87639-44), 3.5 kilometers east of Yokdzonot, Yucatan (KU 71720), and 4 kilometers west-southwest Puerto Juarez, Quintana Roo, Mexico (KU 71721), whereas others, notably from 17 kilometers northeast of Juchatengo, Oaxaca, Mexico (KU 87645), are much paler and lack the dark markings on the caudal musculature. The variation in intensity of pigmentation possibly can be correlated with environmental conditions, especially the amount of light. In general, tadpoles that were found in open, sunlit pools are pallid by comparison with those from shaded forest pools. These subjective comparisons were made with preserved specimens; detailed comparative data on living tadpoles are not available. The relative length and depth of the tail are variable; in some individuals the greatest depth of the tail is about at mid-length of the tail, whereas in most specimens the tail is deepest at about one-third its length. The length of the tail relative to the total length is usually 58 to 64 per cent in tadpoles in stages 29 and 30 of development. In some individuals the tail is about 70 per cent of the total length. On the basis of the material examined, these variations in proportions do not show geographical trends. Probably the proportions are a reflection of crowding of the tadpoles in the pools where they are developing or possibly due to water currents or other environmental factors. Stuart (1948:26) described and illustrated the tadpole of _Smilisca baudini_ from Finca Chejel, Alta Verapaz, Guatemala. The description and figures agree with ours, except that the first lower tooth row does not have a sharp angle medially in Stuart's figure. He (1948:27) stated that color in tadpoles from different localities probably varies with soil color and turbidity of water. Maslin (1963:125) described and illustrated tadpoles of _S. baudini_ from Piste, Yucatan, Mexico. These specimens are heavily pigmented like specimens that we have examined from the Yucatan Peninsula and from other places in the range of the species. Maslin stated that the anal tube is median in the specimens that he examined; we have not studied Maslin's specimens, but all tadpoles of _Smilisca_ that we have examined have a dextral anal tube.