1925] Storer : A Synopsis of the Amphibia of California 
159 
Additional data, indicating 1 possible dates of spawning, are in- 
cluded in the table of adults given in the earlier part of this chapter. 
The larvae of Scaphiopus hammondii attain a large size before 
metamorphosing (pi. 10,' fig. 30). The largest specimens at hand, 
from Long Valley, Mono County, July 13, 1922, measure 71 milli- 
meters in total length. Of this the body length is 31 millimeters and 
the tail 40 millimeters. Some reduction occurs with metamorphosis, 
as completely transformed individuals taken at the same time and 
place measure from 17.5 to 19.2 millimeters in head-and-body length. 
Recently metamorphosed individuals from other localities range from 
16.5 to 31.0 millimeters in head-and-body length. 
Spadef oot toads are notable among salientian larvae for leaving the 
water while the tail is still of considerable size. Two> captured on the 
shore of a pool on Carrizo Plain, San Luis Obispo County, were 29.5 
and 31 millimeters in head-and-body length, while their tail stubs 
measured about 12 millimeters additional. The tadpoles are fairly 
active in the earlier stages of their development, but after the hind 
limbs are well developed and until the tail is resorbed they experience 
some difficulty in maneuvering. 
Development is very rapid with all three species of Scaphiopus. 
Overton (19155) found that eggs of S. holbrookii laid in pools on 
Long Island, New York, on August 4 (1915) hatched on August 7, the 
larvae were almost half-growm by August 14, and fully formed young 
spadefoots were found in one instance on September 4. Strecker 
(1908) says of S. couchn at Waco, Texas, that the eggs hatch in from 
8 to 10 days, the limbs begin to appear on the 20th to 23d day, and 
on the 27th to 30th day the young leave the water with their tails still 
in evidence. 
The earliest eggs laid at Santa Maria in 1923 hatched in not more 
than 7 days and probably not more than 5 days.' A sample collection 
of larvae made 17 days after hatching revealed larvae ranging from 
18.5 to 43 millimeters in total length. These pools dried up before 
the larvae underwent metamorphosis, so it was not possible to follow 
the history through. 
The burrowing reflex is manifested as soon as the young spadefoots 
leave the water. Camp (MS) found that a young individual when 
placed on a piece of wet bread in strong sunlight at once began to 
work its hind feet fore and aft in the manner of an adult spadefoot 
and soon burrowed its way downward and backward into the soft cool 
substratum. The advantage to the species of the early appearance of 
