Fig. 9: Syrrhophus guttilatus (upper left, UIMNH 55519, ×1.4; lower left, UIMNH 55519, ×2.3) and S. marnockii (upper right, TCWC 9317, ×1.4; lower right, TCWC 13510, ×2.1).
Remarks.—Cope (1879) distinguished Malachylodes from Syrrhophus on the basis of the presence of a frontoparietal fontanelle in the holotype of guttilatus. The holotype is a juvenile female and as is the case in the juveniles of nearly all leptodactylids, a frontoparietal fontanelle is present. Firschein (1954) used the presence of the fontanelle to distinguish guttilatus from his petrophilus.
As is clearly evident from the length of the synonymy, I consider a number of currently used names to be synonymous with guttilatus. I have seen the holotypes of all four names and am unable to recognize more than a single species. The holotype of petrophilus is a male, whereas that of smithi is a female. The supposed differences are a reflection of sexual dimorphism in the size of the eye ([Table 5]). The two holotypes, as well as those of gaigeae and Malachylodes guttilatus agree in color pattern.
Schmidt and Smith (1944) named Syrrhophus gaigeae from the Chisos Mountains of the Big Bend region of Texas and compared it only with S. marnockii. Milstead, Mecham and McClintock (1950) synonymized gaigeae and marnockii because they were unable to verify the characters Wright and Wright (1949) used to separate them. Specimens from the Big Bend region differ from those of the Edward and Stockton Plateaus in having a vermiculate pattern, an interorbital bar, and a supratympanic stripe. In these respects they agree with specimens from northern México. Based on limited observations, the Mexican population is yellowish to brownish in life whereas the central Texas population is green in life. Lacking evidence of genetic exchange, the two are held to be specifically distinct.
Fig. 10: Distribution of Syrrhophus guttilatus.
Nearly every specimen examined was infested with chiggers of the genus Hannemania. The greatest concentrations are on the venter, in the groin, and on the thighs. Many specimens have chiggers on the digits and tarsi. The same, or a related, chigger was found on many specimens of Syrrhophus marnockii and a few S. verrucipes, but on no other species of the genus. Mr. Willy Wrenn told me that he has seen heavy infestations of Hannemania on Syrrhophus pallidus. Infestation by Hannemania probably reflects similar ecologies rather than close relationships.