1925] Storer: A Synopsis of the Amphibia of California 153 
Life-history. — The spadefoot toads represent the most extreme 
modification among the Salientia of North America toward successful 
existence under arid conditions. Their requirements with respect to 
water are reduced to a minimum. Shallow temporary rain pools 
suffice for the egg and larval stages which are passed through in a 
remarkably short interval of time. From the time they emerge from 
the water the adults are provided with cutting ‘spades’ on the hind 
feet which enable them to burrow down into the ground and thus to 
escape desiccation. 
Scaphiopus hammondU is the most elusive of the California 
Salientia. Despite the fact that the species occupies a wide range 
of territory in the settled portion of the State, very few of the adult 
animals come to the attention of human beings. Specimens are rela- 
tively uncommon in collections as evidenced by the small series listed 
above, and naturalists who live right in the midst of territory occupied 
by the species are often completely in ignorance concerning the pres- 
ence of the animals. That they thus escape observation is due to two 
traits : the adults are seldom active save under the cover of complete 
darkness, and the spawning activities may occupy only one or two 
nights in a year. 
Only ^recently have the real habits of the spadefoot toads been 
learned. For many years it was believed that the animals spent most 
of their adult life underground and that they came forth, only at 
intervals of several years, for spawning purposes. Thus, Dickerson 
(1906, p. 56) waiting of Scaphiopus holhrookii of eastern North 
America, says : “ . . . these facts are well authenticated : They dis- 
appear with never a stray one left behind, and they may not appear 
again in the same locality for many years.” Recent observations on 
S. holhroohii by Overton (1914; 1915a; 19155) on Long Island, New 
York, and on S. couchii by Strecker (1908) at Waco, Texas, have 
shown that the spadefoots living in those particular localities are in 
evidence for spawning purposes every year, though for only a very 
brief period in any one season. The few facts at hand concerning 
Scaphiopus hammondU in California suggest that the same is true 
with respect to this species. But if the observer does not happen to 
be on hand at the right time and in the right place the animals will 
escape observation entirely. 
The behavior of some adult Scaphiopus hammondU collected by 
the writer at Santa Maria, Santa, Barbara County, on April 10, 1923, 
