92 BULLETIN 160, UNITED STATES NATIONAL MUSEUM 



rips first the inner capsule and then the outer with its egg tooth. E. inoptatus, 

 on the other hand, has a very small egg tooth and one bunch of eggs on which I 

 experimented could not be induced to hatch without the application of water. 

 Then the eggs elongated, the outer capsule broke first and the inner only some 

 time later. It would therefore seem that forms such as E. abbotti may hatch anj- 

 time the encapsuled larva has the strength to rip the capsules, while in nature, 

 E. inoptatus must Avait for the rains. The first species sometimes lays its eggs 

 among reeds in such a position as to be well protected from the rains. The latter 

 always (three observations) lays its eggs in shallow holes in the bank. Such 

 situations become soaking wet with every rain. The eggs of E. inoptatus would 

 therefore become wet long before they are ready to hatch. Thus there is probably 

 a time factor which prevents the recently laid eggs from splitting open at the first 

 soaking. In other Salientia the egg capsules after a long soaking are much less 

 resistant than recently laid ones. 



The habitats of most of the Mexican species of Eleutherodadylus 

 are very imperfectly known. In March, 1895, Nelson and Goldman 

 collected a specimen of E. rugulosus in a small stream in the woods at 

 3,000 feet altitude near Pluma in Oaxaca. On August 30, 1894, they 

 took specimens of mexicanus at an altitude of 10,000 feet in dense 

 growths of grass about springs and little streams in the vicinity of 

 Cerro San Felipe, and during September, 1894, found this species at 

 altitudes varying from 4,000 to 9,500 feet in oak woods on the moun- 

 tains west of Oaxaca. Gadow found rhodopis living on the ground in 

 masses of rotten leaves, in tillandsia clusters, and on green shrubs, as 

 high as 10,000 feet on Citlaltepetl in Vera Cruz. 



KEY TO MEXICAN SPECIES OF ELEUTHERODACTYLUS 



1. A white or silvery white streak edged with black or with dark 

 iron gray extends along upper lip from snout, below eye and 

 tympanum, to fore limb; a light or dusky band across inter- 

 orbital region; upperparts dark brown or dark mahogany 

 brown; limbs with dark, light-edged crossbars; lower parts 

 white, more or less speckled with brown; male with two vocal 

 sacs, indicated externally bj' a fold on each side of throat; 

 first and second fingers equal; fingers and toes slender, with 

 very small terminal disks and fairly strong subarticular tu- 

 bercles; a very distinct vestige of web between the toes; two 

 metatarsal tubercles, the inner oval, the outer round and 

 smaller; plantar surface with small scattered tubercles; a dis- 

 tinct crested tarsal tubercle or ridge about midway but no 

 tarsal fold; the hind limb being carried forward along the body, 

 the tibio-tarsal joint reaches the tip of snout or a little beyond; 

 vomerine teeth in two oblique series behind the level of the 

 choanae; tongue oval, or oblong; snout pointed, projecting 

 beyond mouth; canthus rostralis distinct; loreal region slightly 

 concave; nostril near end of snout; interorbital space a little 

 broader than upper eyelid; tympanum round, very large and 

 distinct, as large as or larger than the eye; skin of upperparts 

 with many small tubercles and plicate rugosities; a faint ver- 

 tebral linear dermal ridge; a pair of converging dorsal dermal 

 ridges present or absent; several other irregular lateral glan- 



