MEXICAN TAILLESS AMPHIBIANS 



21 



transferred it to his new species redifrenis. This specimen was 

 collected on the Rio Nazas in Coahuila by Lieut. D. N. Couch and 

 unfortunately can not now be located in the collection. In this 

 same paper, Cope cited a specimen (U.S.N.M. No. 3713) obtained 

 by Couch at Matamoros in Tamaulipas as the basis for the diagnosis 

 of S. couchii. The other cotype of S. redifrenis (U.S.N.M, No. 3715), 

 which was collected in Tamaulipas by Couch, is marked in the record 

 book of the division of reptiles as having been destroyed. The 

 collections that Cope had in his possession for study so many years 

 were returned to the National Museum after his death, but so far as 

 known not one of these cotypes was ever found. 



This night-prowling spade-foot toad has a somewhat bloated appear- 

 ance in life and frequents lowlands as well as plateaus. It is most 

 frequently observed during the time of the spring rains, when it 

 comes forth to breed in temporary pools and at other times when 

 heavy rains drive it from its burrow. It is well adapted for a subterra- 

 nean and nocturnal life, and at certain seasons may be found half 

 buried in moist earth under some old log. From 350 to 500 eggs are 

 laid in strings, the number in each string varying from 45 to 125. The 

 eggs are attached to grftss, weeds, or roots in shallow water, generally 

 less than 6 inches in depth, and they hatch in 8 to 10 days. The 

 growth of the tadpole is very rapid, and within three weeks the meta- 

 morphosis to the land stage has taken place. Doctor Nelson observes 

 in his field catalogue that hundreds of these spade-foot toads were 

 mating at Acaponeta on June 26, 1897, in a pool of water near the 

 river bank. 



Specimens examined. — Thirty, as follows: 



Scaphiopus couchii 



