136 BULLETIN 160, UNITED STATES NATIONAL MUSEUM 



After I read Mocqiiard's description of Hyla rudis, it became 

 apparent that it was certainly not a Hyla and furthermore that it 

 seemed to agree rather closely with specimens of this species. A 

 reexamination of the type revealed that it was unquestionably a 

 young individual of Pternohyla fodiens. The type of H. rudis 

 (M.H.N. P. No. 373a, parchment label No. 97-217) was collected at 

 Guadalajara in Jalisco by Leon Diguet. The following notes were 

 made on this specimen : Head-and-body length, 34.5 mm. ; tympanum 

 one-half diameter of eye ; top of head flat and rugose ; the hind limb 

 being carried forward along the body, the tibio-tarsal joint does not 

 reach to edge of minute tym.panum; a very faint indication of a tarsal 

 fold; toes scarcely webbed; fingers free; very small adhesive disks; 

 large inner metatarsal tubercle; abdomen and under surface of thighs 

 coarsely areolate or granular. The color pattern described by Moc- 

 quard, the presence of a large internal metatarsal tubercle, as well as 

 other peculiarities noted above are all characters that distinguish 

 P. fodiens from other Mexican hylids. 



A series of 67 of these burrowing tree frogs (A.M.N.H. Nos. 

 12415-12458 ; 12460-12482), all collected in Mexico by Paul D. K. Ruth- 

 ling, are especially interesting, for they range in size from young 

 with a body length of 17.5 mm. (No. 12482) to adults with a 

 head-and-body length of 45 mm. (No. 12457). The young generally 

 have a single pair of black spots on the posterior sacral region in front 

 of the vent, and all except the very youngest have the characteristic 

 splotched upperparts. The shape of the head is about the same in 

 young and in adults, but in the former the ornamentation is less 

 obvious because of the less advanced stage of dermal ossification, and 

 in quite young indi\'iduals the loreal region is oblique and not shelving. 



Nelson and Goldman removed one of these frogs from the stomach 

 of a snake {Leptophis diplotropis) killed at Acaponeta in Nayarit. 

 No field notes on the habits of this frog are available, but Boulenger 

 {op. cit.) has published some observations on a living specimen 

 obtained at Presidio by A. Forrer. He says: 



It is a timid creature, getting very frightened when handled, whilst all other 

 Hylidae 1 have seen alive are very indifferent under similar circumstances. It is 

 slow in its movements, and not a good climber. Its habits are more burrowing 

 than arboreal. It is not able to climb up a glass, but burrows itself deeply in the 

 moss by means of its metatarsal shovels, the movements executed in this pro- 

 ceeding being exactly those of Pelobates. I believe this to be the first instance of 

 an adaptation to both burrowing and arboreal life. 



Specimens examined. — Seventy-eight, as follows : 



