1925] Storer: A Synopsis of the Amphibia of California 
161 
oped. They have the characteristic thick projecting muzzle and 
obscure tympanum.” 
Snyder (1920, pp. 83-84) says that in the vicinity of Pyramid 
Lake, Nevada, Scaphiopus hammondii seems to appear regularly each 
year for breeding. His account is as follows : 
I observed them there in 1911, 1912, and again in 1913. They were first seen 
April 23 to 25, and they were laying eggs May 28 to June 2. 
Their appearance was at once announced by a loud chorus which differed 
markedly from that of Hyla or Bana, being in a lower key, somewhat guttural, 
and a little rasping. It was entirely different from that of Bufo. 
They collected in considerable numbers in the quiet water of irrigating ditches 
and in little ponds, where at night they sprawled out motionless in the water, 
their bright eyes projecting just above the surface. When once found they were 
easily caught, and when placed on the ground they proved to be very slow and 
awkward little creatures, exhibiting haste only when given an opportunity to sink 
into the desert sand. . . . 
On the evening of June 2, 1911, I happened upon a small pond separated from 
the water of Pyramid Lake by a narrow bar. The pond was but a few feet in 
width, and perhaps a hundred feet long. The water was clear and slightly alkaline 
like that of the lake. In it were hundreds of spadefoots depositing their eggs in 
masses one layer deep on the upper surfaces of small rocks. The eggs were not 
piled up after the manner of frogs, nor were they in strings like those of toads. 
One mass presented fresh eggs and likewise others in which development was 
marked, plainly indicating that the mass was made of at least two contributions. 
During the following night a continued croaking chorus was at times plainly 
heard, but it ceased at dawn, and shortly after break of day all the toads had 
disappeared and they returned no more. Diligent search under rocks and in the 
sand nearby was not rewarded by a single specimen. 
The life-history in relation to the environment . — The spaclefoot 
represents the extreme form among the Salientia of California with 
respect to limited moisture requirements. While it occurs in localities 
tenanted by other species of tailless amphibians it there occupies the 
driest local ‘niche,’ and it is able to live successfully in localities 
unsuited by reason of moisture deficiency to other species. The prin- 
cipal features which enable Scaphiopns hammondii to do this are the 
possession of digging equipment in the form of ‘spades’ on the hind 
feet and the instinctive use of these in excavating a subterranean 
retreat in which to take shelter to avoid desiccation. Bufo b. halo- 
philus lives in localities tenanted by Scaphiopns , but the former is not 
able to excavate in the manner of the latter. Of the desert-inhabiting 
toads, Bufo cognatus has a development of metatarsal tubercle com- 
parable with that of Scaphiopus, which suggests that it also may be 
able to burrow as a safety measure. An apparent anomaly is seen in 
the relatively smooth skin of Scaphiopus. Other species of terrestrial 
