PLATE 16 
Fig. 49. Larvae of Hyla regilla (upper left), Rana boylii boylii (upper right), 
and Bufo boreas halophilus, all approaching transformation ; from creek at Lafay- 
ette, Contra Costa County, July 20, 1922. About natural size. 3916. 
Fig. 50. • Egg mass (complete) of Rana boylii boylii from San Pablo Creek 
near Orinda, Contra Costa County, collected April 20, 1923. Natural size. 3990. 
[ 338 ] 
