NO. 1156. VARIATIONS OF HYLA REGILLA— TEST. 481 



Besting, Pahrump, and Vegas springs, and in the Panamint and 

 Charleston mountains. Of these. Hot Springs, the nearest point to the 

 Sierra Nevada, is se])arated from that range by more tlian 40 miles, 

 and like the other sjnings is situated in the midst of an extremely hot 

 and arid desert. An almost equal distance intervenes between Johnson 

 Canyon and Saratoga Springs, showing that in this semiisolated area 

 the species seems to have spread from place to place by means not 

 altogether satisfactorily explained at present. It may be that the dis- 

 tribution was brought about by the great inland lakes formerly existing 

 in Panamint and Death valleys, and that the species, going up the 

 streams flowing into them from various directions, or following the 

 shrinking borders, has stranded where it is now found. At the present 

 time the floods which occasionally swell the dry channels into tem- 

 porary streams, thrusting out into the deserts to soon vanish, may 

 assist in further increasing the range. 



It has also been collected on Santa Cruz and Cerros islands, each 

 nearly 20 miles distant from the mainland. 



Moreover, it may be noticed that in altitude Ilyla reffilla ranges from 

 sea level up to nearly 10,000 feet in the vicinity of Mount Whitney. 

 Thus it occurs from the Lower Sonoran well up into the Boreal Zone, 

 equal to the difference in the latitude between Florida and Labrador, 

 and the extension of its range is thus second to that of no other hyla 

 in North America. Within its range it is quite a common species, 

 especially frequenting marshy land and the edges of springs, ponds, 

 and other bodies of water. 



Byla regilla is a moderate-size species, the largest specimens in the 

 collection measuring 47 mm., or not quite IJ inches in length. The 

 head is small to medium, rather more pointed than rounded in front, 

 and shorter than broad, with the width at the tympana about one-third 

 of the total length. In profile it is inclined to be flat, with the snout 

 rounding. Kyes projecting only moderately, and tympanum about half 

 the size of the orbit. A small fold of skin, beginning at the posterior 

 angle of the eye, runs over the tympanum to above the arm. Another 

 well marked fold crosses the breast, Just at the posterior edge of the 

 arms, into which it is continued a short distance. The skin everywhere, 

 except on the sides of the head, is covered with minute elevations, 

 which on the abdomen, lower surface of thighs, and less on the throat, 

 are crowded together as granulations. On the upper surface numerous 

 larger papules or tubercles are intermingled with the smaller, becom- 

 ing fewer on the head. Gular sac quite prominent in most males. The 

 limbs are moderate. The fingers are free, except that a very slight 

 web connects their bases. Tiie disks vary from small to moderate. 

 The length of the tibia is about half the total length. The webbing of 

 the toes varies considerably, as do the disks. There is a small outer 

 metatarsal tubercle, and a larger, marked inner one. A thin ala extends 

 along the inner side of the tarsus. 

 Proc. N. M. vol. xxi .31 



