MEXICAN TAILLESS AMPHIBIANS 39 



probable that Girard may have assumed that this range was so 

 situated. It would seem that specimens collected along the route 

 between Monument No. 14 on Sierra de la Union and the water holes 

 of the Nariz Mountains were placed in one container and so labeled. 

 The Sierra de la Union is shown on modern maps as Sierra de Moreno, 

 and this range of mountains crosses the boundary line between 

 Arizona and Sonora about 10 miles west and south of San Miguel in 

 southern Pima County. The Sierra de la Nariz crosses the boundary 

 line about 35 miles distant in a northwest direction. No other toad 

 of this species collected by Schott is entered in the museum catalogue. 



An examination of the catalogue of the division of reptiles reveals 

 that another specimen (U.S.N.M. No. 2572) was available to Girard at 

 the time the description was written. This was collected at old Fort 

 Yuma, Calif., by Maj. George Henry Thomas, and is designated in 

 the museum catalogue as the type of Bufo alvarius. Old Fort Yuma 

 is located near the junction of the Gila and Colorado Rivers and thus 

 lies in the "Valley of Gila and Colorado." The fact that Major 

 Thomas had no official connection with any of the parties working 

 on the survey of the boundary line does not suffice to explain the 

 omission of this particular specimen, for a bat received in the same 

 shipment with this toad is listed by Baird. The collection made by 

 Thomas was received at the Museum in 1856. 



It is quite certain from the notation made by Baird that the speci- 

 men figured on the plate accompanying the original description of 

 Bufo alvarius came either from some spot between Sierra de la Union 

 (Sierra de Moreno) and Charcos de la Nariz, or else from one or the 

 other of these localities. These mountain ranges are located on the 

 divide between the drainage of the Gila River in Arizona and that 

 of the Rio Concepcion in Sonora. It is equally certain that the speci- 

 men which was collected by Major Thomas at Fort Yuma, Calif., 

 had been received by the museum at least three years prior to the 

 publication of Girard 's description. 



It is unfortunate that the type or cotypes of Bufo alvarius are not 

 designated by the original describer. The usual procedure is to 

 select as the lectotype or as the cotypes the specimen or specimens 

 that were seen by the original describer before his description was 

 published. In this instance one has to assume that all the material 

 available in the Museum from the region covered by the boundary 

 survey report was placed at Girard's disposal. If one takes Girard's 

 "Valley of Gila and Colorado" at its face value, then the specimens 

 taken by Schott and labeled as coming from "Sierra de la Union y 

 Charcos de la Nariz" must be disregarded, inasmuch as they were 

 not obtained at the type locality. On the other hand, if one insists 

 that the type or cotypes were collected by Schott as stated by Girard, 

 then the specimen collected by Major Thomas at Fort Yuma in the 



