HAND.--The species in the _Ptychohyla euthysanota_ group have a vestige of web between the first and second fingers; the other fingers are about one-third webbed. Breeding males have a cluster of horny nuptial spines on the thumb. The spines are largest in _P. spinipollex_ (Fig. 1) and vary in number from 35 to 66 (average 47.4) on each thumb. In the other species of the _Ptychohyla euthysanota_ group the spines are smaller and usually more numerous; the numbers of spines on each thumb (means in parentheses) in members of this group are: _P. euthysanota euthysanota_, 44-143 (83.8); _P. euthysanota macrotympanum_, 40-110 (63.0); _P. leonhardschultzei_, 24-80 (54.7). The species in the _Ptychohyla schmidtorum_ group have no web between the first and second fingers and only a vestige of web between the other fingers. Furthermore, these species lack nuptial spines in breeding males. Like the usual horny excrescences on the thumbs of many species of frogs, the horny spines on the thumbs of members of the _Ptychohyla euthysanota_ group are seasonal in development. TABLE 1.--VARIATION IN CERTAIN CHARACTERS IN THE SPECIES OF PTYCHOHYLA. (MEANS ARE IN PARENTHESES BELOW THE RANGES.) Key to Table Columns A) Number of specimens B) Maximum snout-vent length C) Tibia length/Snout-vent length D) Tympanum/Eye E) Vomerine teeth ==================+========+======+=======+=========+=========+======= Species | Sex | A | B | C | D | E ------------------+--------+------+-----------------+----------------- | | | | | | _P. euthysanota | [Male] | 17 | 38.1 |44.4-55.0|48.6-63.8| 4-6 euthysanota_ | | | | (48.7) | (56.3) | (5.1) | | | | | | |[Female]| 15 | 53.3 |46.5-56.6|42.9-56.4| 6-18 | | | | (51.4) | (51.4) | (9.6) | | | | | | _P. euthysanota | [Male] | 5 | 38.0 |48.8-52.0|50.0-57.1| 0-4 macrotympanum_| | | | (50.2) | (54.1) | (2.6) | | | | | | |[Female]| 5 | 44.8 |46.4-54.1|48.7-58.9| 8-10 | | | | (50.2) | (53.7) | (9.2) | | | | | | _P. leonhard | [Male] | 16 | 35.6 |48.8-56.1|48.7-61.9| 6-9 schultzei_ | | | | (51.2) | (52.1) | (6.5) | | | | | | |[Female]| 3 | 41.6 |52.3-59.5|47.5-48.6| 7-12 | | | | (54.7) | (48.1) | (9.5) | | | | | | _P. spinipollex_ | [Male] | 32 | 41.2 |46.9-53.1|45.0-55.2| 3-7