MEXICAN TAILLESS AMPHIBIANS 87 



Now, considering that L. albilabris occurs upon more than one island, it is 

 necessary to postulate a series of unlikely events to explain its accidental occur- 

 rence. It is more probable that the Porto Rican and maniland individuals 

 have by some fortuitous parallelism become indistinguishable if they originally 

 belonged to different stocks or if both were derived from the same stock then 

 they have preserved their identity in parts of their range and varied with isolation 

 in other parts. The occurrence in the East Indies of Rana rnacrodon in the 

 greater Sunda Islands and New Guinea, and of Rana modesta, a deiivative of 

 R. rnacrodon in Celebes is a case of similar distribution. The Lesser Antillean 

 species are almost certainly not introduced, since Labat informs us that frogs 

 (L. pentadadylus) were a common article of food in Martinique and other islands 

 as early as 1724. That they probabl}"^ belonged to this species is shown by his 

 stating that they lived in the woods and not in the water and by his description 

 of their colors. The occurrence of a peculiar Leptodactylus upon Haiti, and 

 there is evidence that a species occiu's upon Cuba also, is not as astonishing as 

 appears at first. 



Schmidt ^^ contributes the following notes on the life history of 

 this species. 



At Coamo Springs, on the terrace behind the bathhouses of the hotel, the water 

 of some of the springs forms a permanent rivulet at the base of the cliff. Lep- 

 todactylus albilabris was abundant on the terrace, beneath loose stones, and under 

 a large stone at the edge of the creek, the writer found, on August 27, 1919, a 

 shallow, rounded excavation, 6 or 7 cm. in diameter and about 3 cm. deep, filled 

 with a mass of white foam, in which were the small tadpoles of this species (12 

 mm. in length, bodj' 3-4 mm.). There were between 75 and 100 tadpoles in the 

 mass, by no means confined to the central hollow, which was present, as in the 

 foam mass described by Stejneger. The bottom of the excavation was about 

 3 cm. above the water level. Two similar excavations were discovered in the 

 immediate vicinity, in the same relative position with reference to the water, 

 but empty. On August 29, near Bayamon, a small mass of foam, between 3 

 and 4 cm. in diameter, containing similar tadpoles, was noted under a stone on a 

 hilltop, with no water whatever in the neighborhood. On October 1, near the 

 forester's cabin on El Yunque, at about 1,200 feet, a nest of this species was 

 observed beside a pool of standing water (also at a slightly higher level than that 

 of the water) under a rotten log. This nest contained between 150 and 200 eggs, 

 uniformly distributed through the foam, and with no central hollow. It was 

 somewhat larger than those previously observed, measuring 8 cm. in diameter. 

 The eggs are light yellow and measure 2.5 mm. to 3 mm. in diameter. The 

 smallest tadpoles taken swimming at large measured 6 mm. in body length, which 

 probably represents their size at the time they escape from the foam. It is 

 evident that the tadpoles usually will be washed from the nest into the adjacent 

 water by a flood or heavy rain. The location of the small nest away from water 

 was probably a mistake on the part of the frog, and the nest described by Stej- 

 neger under water probably had been covered by a rise in the creek after the 

 deposition of the eggs. The largest larvae, nearly ready to transform, measure 

 13 mm. from snout to vent. The V-shaped dorsal markings are already evident 

 in the tadpoles at this stage. The median dorsal white line is probably an adult 

 character. 



35 Schmidt, K. P., Scientific survey of Porto Rico and the Virgin Islands. New York Acad. Sci„ vol. 10, 

 pt. 1, Amphibians and land reptiles, pp. 41, 42, 1928. 



