HERPETOLOGY OF ZUNI MOUNTAINS — GEHLBACH 



271 



group or sex. The validity of such ratios in terms of isometric growth 

 of the parotoid gland and sexual dimorphism can be tested (fig. 7). 

 It may be seen that juvenile specimens have a relatively larger gland 

 and that gland width is more variable than length. No sexual 

 dimorphism is apparent, but females are too few to demonstrate this 

 adequately. In juveniles of less than approximately 30 mm. snout- 

 vent, the cranial crests often are barely discernible, and the frontal 

 area of the cramium undeveloped. These featm-es and the parotoid 

 gland, therefore, should be utilized to separate larger specimens only, 

 preferably sexually mature adults (table 4). 



.14 



.12 



.10 



.6 



.24 



k A 



A AA 



A A 



A 



A A 



O • 



•";• 



••/ 



•o 



.20 



.16 



AA 



A A 



A 



• O 

 O • 



o«« • o • 



• • • 



20 30 40 50 60 70 

 SNOUT- VENT LENGTH mm. 



80 



90 



100 



Figure 7.-Relationship of parotoid gland length/snout-vent length (lower symbols) and 

 parotoid gland width/snout-vent length (upper symbols) to body size in Bufo woodhousei 

 from the Zuni region. 



# Sexually mature males Q Sexually mature females A Juveniles 



The larvae of B. woodhousei have been collected throughout the 

 summer months in slowly running streams, potholes, and cattle tanks. 

 A sample of 12 taken at 7800 feet, July 3, 1959, are 7-12 (x 9.4) mm. 

 body length; they have hindlimb buds. One day later, at 7100 feet, 

 12 larvae with well-developed legs and complete tails were collected; 

 they measure 15-17 (15.7) mm. and approximate the size of trans- 

 forming B. woodhousei from northern Arizona (Wright and Wright^ 

 1949, p. 209). Six recently metamorphosed individuals, 13-19 (x 

 16.9) mm. snout-vent, were found on August 8, 1957, at 7000 feet. 



