+-------------------+------------+--+----------+------------+-----------+ | | | | |Tibia length|Head length| | Species | Sex | N|Snout-vent+------------+-----------+ | | | | length | Snout-vent |Snout-vent | | | | | | length | length | +-------------------+------------+--+----------+------------+-----------+ | _B. marmoreus_ | Male |15|61.5-72.5 | 35.9-41.6 | 28.3-33.3 | | | | | (65.2) | (39.0) | (31.6) | +-------------------+------------+--+----------+------------+-----------+ | _B. perplexus_ | Male |20|50.0-59.0 | 33.7-38.1 | 26.4-31.1 | | | | | (54.9) | (36.4) | (29.5) | +-------------------+------------+--+----------+------------+-----------+ | _B. marmoreus_ | Female | 7|68.0-76.0 | 33.0-36.8 | 26.8-32.6 | | | | | (70.7) | (34.7) | (29.6) | +-------------------+------------+--+----------+------------+-----------+ | _B. perplexus_ |Female | 6|64.1-69.8 | 32.4-36.9 | 25.1-29.0 | | | | | (66.8) | (35.5) | (27.5) | +-------------------+------------+--+----------+------------+-----------+ Taylor (1943a:347) described _Bufo perplexus_ from Mexcala on the Río Balsas in Guerrero. Among the many paratypes are specimens from Tonolá, Chiapas, and Tehuantepec, Oaxaca. These apparently were referred to _perplexus_ solely on the nature of the cranial crests. All of the specimens examined during the course of the present study from the lowlands of Veracruz and from the Pacific lowlands from Sinaloa southward to Chiapas are referable to _Bufo marmoreus_; those from the Balsas-Tepalcatepec Basin are referable to _Bufo perplexus_, as defined above. Ten specimens from Chilpancingo, Guerrero (UMMZ 115352), do not readily fit either species. Perhaps there is gene exchange between the inland and coastal populations through the relatively low pass at Chilpancingo, at the mouth of the Río Balsas, and near the convergent headwaters of the Río Coahuayana and Río Tepalcatepec in southern Jalisco. If this can be demonstrated, then _Bufo perplexus_ would have to be considered as a subspecies of _Bufo marmoreus_, instead of an allopatric species. ~Bufo perplexus~ Taylor _Bufo perplexus_ Taylor, Univ. Kansas Sci. Bull., 29:347, October 15, 1943.--Balsas River near Mexcala, Guerrero, México. Aguililla (2); Apatzingán (42); Buena Vista (5); Capirio (3); La Playa (25); Lombardia (6); Nueva Italia (9); Río Cancita, 14 km. E of Apatzingán; Río Tepalcatepec, 27 km. S of Apatzingán; San Salvador (4); Tzitzio; Volcán Jorullo. ~Bufo occidentalis~ Camerano