922 16. CROTALIDZ 
De Luz, Dulzura, El Nido, Witch Creek, Poway, Escon- 
dido, La Jolla, and at Mountain Spring. 
In northern Lower California, it is known to occur near 
Ensenada, San Quentin, San Tomas, Matomi, Agua Escon- 
dito, Santa Catalina, San Matias, Turtle Bay, San Salado 
Canyon, and in the San Matias, Cocopah and San Pedro 
Martir Mountains, and on Cerros Island. It has been found 
also on Angel de la Guardia, South San Lorenzo, San Mar- 
cos and Monserrate islands in the Gulf of California. 
Habits—This large, heavy rattlesnake is common on 
the coast slopes of southern California and northern Lower 
California. It inhabits chiefly chaparral-covered and rocky 
hill-slopes. It is reported as seen well up in bushes in Reche 
Canyon. Atsatt states that one was extremely active when 
found at daylight in the morning of August 23, 1908, at 
Dos Palmos Spring. Evidently it was not chilled by the 
night temperature. Another very active and demonstrative 
rattler was seen, but it retreated into a cleft in the rocks, 
from which it could not be dislodged. 
Regarding the length of time an individual of this 
subspecies may continue to rattle without apparent external 
stimulus, Dr. Wm. E. Ritter writes: 
“The snake was some 20 or 30 feet from a trail on which 
I was slowly and quietly walking, and discovered itself to 
me by setting up a vigorous whir. As it was partly conceal- 
ed by vegetation I should certainly have passed it by un- 
noticed but for its noise. In this instance its “warning” 
would surely have resulted in its death were I a sharer in 
the usual vengefulness against rattlesnakes. As a matter 
of fact I did nothing to disturb his peace of mind except to 
move around in various ways on my trail for the purpose of 
learning something about the rattle business. 
“That the animal was keenly watching my every move- 
