MEXICAN TAILLESS AMPHIBIANS 103 



elevated some distance above the ground. If its tracks could be seen, they would 

 show impressions of the soles and long toes, of the palms and long fingers only. 

 It moves about slowly and seriously in this stilted fashion, a grotesque little 

 creature indeed. Its grotesqueness is enhanced bj'^ the transversely elongated 

 spots of the back, set in their light pink background like two staring eyes. 



This species lives in fissures of the limestone cliffs along the borders of the first 

 plateau region of Texas. The method of proceeding with body elevated, instead 

 of dragged on the ground, is perhaps correlated with its habit of living among the 

 limestone rocks. 



Some additional observations on the breeding habits of the Texan 

 robber frog have been piibhshed by Strecker : ^^ 



Lilhodytes latrans has in all probability an extensive range, but, on account of 

 its peculiarly secretive and nocturnal habits, has been overlooked by the most emi- 

 nent herpetologists who have visited Texas. Its distribution is entirely depend- 

 ent on the presence of the exposures of white limestone which enclose many of the 

 streams of the central and southern sections of the State. 



It is a land animal, hiding in caves and fissures during the daytime, and, except- 

 ing during the brief breeding period, venturing abroad only at night. Breeding 

 in water-filled pockets and hollows in the rocks and in the rocky beds of small 

 streams, it does not appear to be perfectly at home in the water at any time and 

 specimens observed by me made no attempt to conceal themselves by diving 

 but swam clumsily across small pools and sought to escape by leaping up the bank 

 on the opposite side. A breeding pair remain in copula close in to the bank. 

 The masses of water-soaked leaves which line the edges of the pools and hollows 

 serve them for the purpose of floating their fertilized eggs. * * * 



This species breeds unusually early in the year. Marnock informed Cope that 

 the eggs were hatched in winter. Here in central Texas the breeding season is 

 later than it is in Bexar County and the eggs are deposited early in February. 

 If the eggs were deposited before the 9th of that month in the present year, they 

 were subjected to some of the hardest freezes we have had in years. On the 9th 

 and 10th the ground was covered with two inches of water. A few days later 

 the weather was warm and clear and melted snow filled the hollows in many of 

 the gulches that are usually dry at this season. 



On March 5 a number of tadpoles were found in small pools in the gully 3 miles 

 north of town. They were in two stages, the larger ones having the hind limbs 

 well developed. In form these larvae were short and round bodied, with slender, 

 but rather short, tails. In a specimen 36 mm. in total length, the distance from 

 muzzle to anus was 14 mm. In a smaller example, the tail was only 4 mm. longer 

 than head and body. * * * 



These little poUy wogs are very active and on being disturbed conceal themselves 

 among leaves in the bottoms and on the sides of the pools. The larger ones are 

 unusually wary and it is a difficult matter to capture them even with a dip net. 

 * * * By the 19th of March the larger tadpoles had become fuUy developed 

 frogs and left the water with their short tails still in evidence. They were slightly 

 over a third as large as full-grown adults. The complete metamorphosis must 

 not take over six weeks, if we are to judge by the length of time required for other 

 frogs to transform after the first appearance of the hind limbs. 



The indirect development described by Strecker and the presence 

 of narrow toes have led Noble *^ to infer that this species does not 



" strecker, J. K., jr., Notes on the robber frog (Lithodytes latrans Cope). Trans. Acad. Sci. St. Louis, 

 vol. 19, no. 5, pp. 73-79, June 14, 1910. 



« Noble, Q. K., An outline of the relation of ontogeny to phylogeny within the Amphibia, I. Amer, 

 Mus. Nov., no. 16.5, pp. 14, 15, Apr. 16, 1925. 



