HERPETOLOGY OF ZUNI MOUNTAINS — GEHLBACH 267 



and S. homhijrons was considered a distinct species by Schmidt 

 (1953, p. 59) and Stebbins (1951, pp. 202-218; 1954, pp. 92-94). 

 Stejneger and Barbour (1943, pp. 37-39), Tanner (1939), and Zweifel 

 (1956) separated the three forms as species, an arrangement which 

 I favor on the basis of available Zuni material. I further concur 

 with Zweifel (1956, p. 37) in suggesting that S. bombifrons and S. 

 intermontanus may be conspecific. Blair (1956) thought the call 

 of S. intermontanus to be more nearly like that of S. bombifrons than 



S. hammondi. 



The measurements of 41 adult spadefoots, considered to be *b. 

 hammondi on the basis of flattened frontoparietals, are summarized 

 (table 4). Males are somewhat larger than females as noted in 

 S. holbrooki by Pearson (1955) . Such sexual dimorphism is frequently 

 reversed in other anurans. Specimens from the Miocene lava plains 

 near El Morro National Monument are larger and darker in color 

 than those from light, sandy soils near Thoreau and Grants. When 

 compared with individuals "from other southwestern states, the total 

 series is considerably smaller in all respects (see Tanner, 1939, p. 17). 

 All adults of S. hammondi have red-tipped dorsal tubercles, and 

 most have small dark spots or blotches scattered over the dorsum. 



Four adults of S. bombifrons and two of S. intermontanus ^ are 

 distinct when one considers relative elevation of the frontoparietal 

 bones as the best criterion for separation (see Zweifel, 1956, pp. 

 35-37). Unlike S. hammondi, these six specimens possess two 

 continuous dorsolateral light stripes that diverge posterolaterally 

 from the occiput. The S. bombifrons measure 48, 49, 50, and 52 mm. 

 snout-vent; the S. intermontanus, 46 and 51 mm. These individuals 

 are, therefore, larger than most S. hammondi from the Zunis. A 

 size difference between S. hammondi and S. bomUfrons-S. intermon- 

 tanus may serve as an isolating mechanism in this area of sympatry. 

 Lowe (1954) has discussed this factor in Scaphiopiis of south-central 

 New Mexico. 



S. intermontanus is recorded here from New Mexico for the hrst 

 time. The specimens were taken at 7200 feet in an area of mixed 

 grass and one-seed junipers. The present localities for S. bombifrons, 

 at 6400 to 7200 feet in the Plains Life Belt, are near the extreme 

 northern limit of its range in New Mexico; hence, an ideal situation 

 for studying the relationships of S. bombifrons and S. intermontanus 

 exists in the Zunis. Conclusive evidence that these two species are 

 isolated reproductively rests with the collection of additional material 

 in this critical area. 



The spawning of S. hammondi in rainpools, cattle tanks, roadside 

 ditches, and canyon-bottom potholes was observed during periods of 

 heavy rainfall in July and August. Breeding sites were located in 



