56 BULLETIN 160, UNITED STATES NATIONAL MUSEUM 



low spiny tubercles on the back. The range of individual variation in 

 B'u;fo marinus has been discussed by Ruthven^^ and Noble. '^ 



Adults of Bufo marinus are the largest of the true toads. Miranda- 

 Ribeiro ^* states that specimens with a head-and-body length of 220 

 mm. have been taken in Brazil and that this species ranges southward 

 to the Patagonian district. These large toads are nocturnal in their 

 habits and hide under fallen tree trunks, matted leaves, and stones, or 

 burrow into loose soil. 



Atmospheric conditions seemingly influence the time of breeding 

 of this species. Egg laying may commence as early as February, if 

 there has been plenty of rain, but may be delayed until July in regions 

 of continued drought. The breeding season also varies according to 

 locality. Tadpoles have been noticed in Barbados in the pools during 

 August and February, while in Bermuda the eggs are usually laid 

 during April. From the observations made by Ruthven,'^ it would 

 appear that 45 days are required for development from egg to adult. 

 The eggs that Mark ^® kept under observation hatched in a few hours 

 less than 4 days. 



The poisonous nature of the glandular secretions of some of the 

 toads has been investigated by Madame Phisalix,^'' and she has dis- 

 cussed the kinds of toxins that are present. Few actual observations 

 on the action of this secretion on other animals, however, have been 

 published. It is therefore of interest to review a short paper by 

 Dodds.^* Near the end of July, 1922, at Los Mochis in northern 

 Sinaloa, a small terrier dog was observed teasing a large toad, pre- 

 sumably Bvfo marinus. At last the dog caught the toad by the back 

 and "although the dog's mouth was not in contact with the toad for 

 more than an instant, he immediately lost all interest in the animal.'^ 

 The dog refused water and "in about a minute's time showed signs 

 of weakening and general paralysis. He sank to the ground with his 

 legs spread out, writhing and whining with pain, and unable to recog- 

 nize his master. During this time he was able to push himself along 

 the ground, gradually becoming weaker and very rigid, with eyes 

 greatly protruding and respiration and heart action exceedingly rapid. 

 After twenty minutes he was somewhat quieter as if he was going to 

 die." Castor oil was then administered to the terrier and an hour 

 later the dog apparently was quite normal. 



Specimens examined. — One hundred and four, as follows: 



12 Ruthven, A. Q., The amphibians and reptiles collected by the University of Michigan-Walker 

 Expedition in southern Vera Cruz, Mexico. Zool. Jahrb. (Syst. Abt.), vol. 32, pi. 4, p. 309, 1912. 



"Noble, G. K., Bull. Amer. Mus. Nat. Hist., vol. 38, art. 10, p. 333, 1918. 



" Miranda-Ribeiro, A. N., Archiv. Mus. Nac. Rio Janeiro, vol. 27, pp. 134, 216, 217, 1926. 



" Ruthven, A. Q., The breeding season of Bufo marinus (L.) in Demerara. Copeia, no. 31, pp. 43, 44> 

 May 24, 1916. 



'« Pope, P. H., The introduction of West Indian Anura into Bermuda. Bull. Mus. Comp. Zool., vol. 61, 

 no. 8, pp. 123, 124, June, 1917. 



" Phisalix-Picot, M., Animanx venimeux et veuins, vol. 2, pp. 1-174, 1922. 



•* Dodds, C. T., A note on Bufo marinus. Copeia, no. 114, pp. 5, 6, Jan. 20, 1923. 



