212 University of California Publications in Zoology [Vol. 27 
I am unable to find more than two size-groups in the metamor- 
phosed individuals at hand, which suggests that Hyla arenicolor 
reaches its adult size and breeds when two years old. The breeding 
animals collected April 15, 1923, on Snow Creek are about the size of 
the smallest individuals listed in the table of measurements given 
above. 
Wright (1920, pi. XVII, fig. 2) has figured some eggs which are 
labeled ‘ ‘ The stalked eggs of the desert tree toad ( ? ) . ” There was 
evidently doubt in his mind as to the exact identity of the eggs. I 
am loath to believe that the eggs figured could be those of Hyla areni- 
color. The figure is not clear but the stalking is evident. None of 
the water-spawning salientians with which I am familiar produce 
pedunculated eggs. 
Englehardt (1917, pp. 5-6) found Hyla arenicolor abundant in 
clear shallow pools on the course of a creek near the Bright Angel 
trail in the Grand Canon of the Colorado, Arizona. On June 9 and 
10, 1916, the tree-toads were numerous and some were still mating. No 
ova, but many tadpoles, were found in the water. ‘ 4 The tadpoles were 
about one inch long [thus probably about two-thirds grown] ; uni- 
formly dark gray above and iridescent light gray below ; tail broad, 
heavily marbled, dark gray; eyes golden.” The same author (Engle- 
hardt, 1918, p. 79^) makes the statement that near Bellevue, Washing- 
ton County, Utah, in [May or June?] 1917, “ova [presumed to be of 
this species] were observed in the form of small clusters deposited 
along the margin of pools. The tadpoles, at first black, later become 
mottled gray when they resort to deeper water.” 
The life-history in relation to the environment. — The range of 
Hyla arenicolor is a splendid example of local discontinuous distribu- 
tion. Although its general range extends from Texas to the Pacific 
Ocean and from central Mexico to Utah, the actual area occupied by 
the species is only a very small portion of the territory indicated. 
Within the mountains of southern California it is an inhabitant of 
many canons. From the eastern scarp of the San Jacinto Mountains 
and the mountains of eastern San Diego County there is a big gap to 
the eastward which, so far as present information indicates, is entirely 
uninhabited by the species. The next nearest station of record is Fort 
Whipple, Arizona. The condition indicated for California obtains 
throughout the entire range of the species. Its actual territory of 
occupation is quite ‘spotty.’ Thus far no differences worthy of 
nomenclatural recognition have been advanced to separate any of the 
