In the course of preparing an account of the species of Eleutherodactylus occurring in México and northern Central America, it became necessary to reëxamine the status of the genus Syrrhophus and its nominal species. It soon became evident that there were more names than species, that some previously regarded species were geographic variants, and that the eastern and western groups (complexes here) were artificial divisions of the genus. I conclude that there are seven species (one polytypic) of Syrrhophus in eastern México, Texas, and El Petén of Guatemala, and seven species (one polytypic) in western México. The current status of each of the 23 names correctly assigned to the genus is presented in [Table 3].
The fourteen species recognized by me are placed in five species groups. Two of these groups are presently placed in the western complex (modestus and pipilans groups) and three in the eastern complex (leprus, longipes and marnockii groups). The two complexes do not correspond exactly with the eastern and western groups of Smith and Taylor (1948), Firschein (1954), and Duellman (1958) since S. rubrimaculatus is now associated with the eastern leprus group.
The definitions and contents of the five species groups are as follows:
leprus group: digital pads not or only slightly expanded, rounded in outline; first finger longer or shorter than second; snout acuminate or subacuminate, not rounded; outer metatarsal tubercle conical; digits lacking distinct lateral fringes.
content: cystignathoides, leprus and rubrimaculatus.
longipes group: digital pads widely expanded, triangular in outline; first finger shorter than second; snout acuminate; outer metatarsal tubercle not conical; digits bearing lateral fringes.
content: dennisi and longipes.
marnockii group: digital pads expanded, rounded to truncate in outline; first finger equal in length to second or slightly shorter; snout rounded; outer metatarsal tubercle not conical; digits lacking lateral fringes; generally stout-bodied frogs.
content: guttilatus, marnockii, and verrucipes.
modestus group: digital pads expanded, truncate in outline; first and second fingers subequal in length, first usually slightly shorter than second; snout subacuminate; inner metatarsal tubercle twice as large (or larger) as outer metatarsal tubercle; digits bearing poorly-defined lateral fringes.
content: interorbitalis, modestus, nivocolimae, pallidus, and teretistes.
pipilans group: digital pads not or only slightly expanded, truncate in outline; first finger equal in length to second; snout subacuminate; metatarsal tubercles subequal in size; digits lacking lateral fringes.
content: pipilans.
Acknowledgments.—For loan of specimens, I am indebted to Richard J. Baldauf, Texas A & M University (TCWC); W. Frank Blair, University of Texas (TNHC); Charles M. Bogert and Richard G. Zweifel, American Museum of Natural History (AMNH); James E. Böhlke and Edmond V. Malnate, Academy of Natural Sciences of Philadelphia (ANSP); Robert F. Inger and Hymen Marx, Field Museum of Natural History (FMNH); Ernest A. Liner (EAL); Michael Ovchynnyk, Michigan State University collection (MSU); James A. Peters, United States National Museum (USNM); Douglas A. Rossman, Louisiana State University Museum of Zoology (LSUMZ); Hobart M. Smith, University of Illinois Museum of Natural History (UIMNH); Charles F. Walker, University of Michigan Museum of Zoology (UMMZ); and John W. Wright, Los Angeles County Museum (LACM). Specimens in the collection at the University of Kansas Museum of Natural History are identified as KU. The abbreviations EHT-HMS refer to the Edward H. Taylor-Hobart M. Smith collection and FAS to the Frederick A. Shannon collection. The type-specimens from these collections are now in the Field Museum of Natural History and the University of Illinois Museum of Natural History.