102 BULLETIN 160, UNITED STATES NATIONAL MUSEUM 



notes on E. augusti, which are taken from the field notes of L^on 

 Diguet and from which the following is quoted (translation) : 



H. augusti appears to be essentially nocturnal, which explains its rarity in 

 collections. Cope had already made known some facts regarding their habits, 

 after the data furnished to him by Mr. G. W. Marnock, who discovered it inTexas. 

 In confirming these details for me, Mr. Diguet has been good enough to add to 

 them the following information: "This batrachian is encountered in the territory 

 of Tepic in damp ravines at the commencement of the rainy season; that is, the 

 end of June and July. Its voice is resounding and can be heard at a distance 

 after sunset. At this time, it is found attached upon certain smooth-barked 

 trees, such as the Burseras, the color of which is the same as that of the animal." 



This last observation of Mr. Diguet has its importance, in that it establishes for 

 us the significance of the ventral disk: It is, undoubtedly, an adhesive disk. 

 The fingers, in fact, lack terminal disks and are only feebly swollen at their 

 extremities; the animal therefore can not maintain itself along vertical surfaces 

 except by means of this ventral disk. Furthermore as this disk can not be other 

 than an organ of attachment, the progression of this batrachian upon the trunks 

 of trees or in the vertical cracks of rocks, where it has been found by Mr. G. W. 

 Marnock in Texas, must be effected by leaps: This is actually the case and Mr. 

 Diguet has seen it constantly leaping from one branch to another when it tried to 

 hold on. 



Mr. Diguet has never encountered H. augusti during the day, but [only] at 

 night with the aid of a light. He was able to capture eight specimens, seven males 

 and one female, in the vicinity of small puddles of water on the western slope of 

 the Cerro San Juan, territory of Tepic. He had at first grasped a male, next a 

 female, whose sex he identified by the presence of ovaries loaded with eggs, which 

 the transparency of the abdominal wall let be seen; he held this female upon 

 the ground and saw arriving successively 6 other males which followed her and 

 which he seized. 



Inasmuch as Mocquard makes reference to the field observations 

 of Marnock published by Cope and since E. augusti and E. latrans 

 seem to be quite closely related, quotations from accounts dealing 

 with the habits and life histories of E. latrans are here given. 



In his preliminary notice of the discovery of the Texas cliff frog, 

 Cope writes ^* that — 



It lives in fissures in the limestone cliflFs that stretch across that section of the 

 State. According to Mr. Marnock the eggs hatch out in the winter, and the 

 tadpoles live in the rainwater which is caught in the shallow holes in the rocks, 

 far from the creeks. During the winter the adults are very noisy, the rocks 

 resounding in the evening with their dog-like bark. 



Miss Dickerson ^^ has published a very interesting account of this 

 species, from which the following is taken: 



This smooth frog-like batrachian attains a surprisingly large size for one so 

 delicately built. The arms and legs are peculiarly slender, and look out of pro- 

 portion when seen on a frog three and a half inches long. 



In fact, Lithodytes latrans is a very curious-looking creature. It rests on hands 

 and feet only, the tarsus and other parts of the legs as well as the body being kept 



" Cope, E. D., Amer. Nat., vol. 12, no. 3, p. 186, Mar., 1878. 

 «• Dickerson, M. C, The frog book, p. 164, 1906. 



