45. MICRURUS 891 
Teenpthy toa ws 25s 367 
Tuength, of, «tail 22 oe a jth oat 24433 
Distribution—This species has been found north to 
southern Utah and south in Mexico to Batopilas, in Chihua- 
hua, and Guaymas, in Sonora. It has been taken on Tiburon 
Island, in the Gulf of California. 
In the United States, it has been secured in southern 
Utah, in Saint George Canyon, near the Arizona line. 
In Arizona, specimens have been collected in Cochise 
(Fort Bowie, Fort Huachuca), Santa Cruz (Nogales), 
Pima (Tucson, Mineral Hill, Rosemont, Sabino Canyon in 
the Catalina Mountains), Gila (San Carlos), Yavapai (Fort 
Whipple, Date Creek), and Mohave (Signal), counties, and 
at Warsaw Mill on the Mexican boundary line. 
Although it seems to be restricted to the Lower Sonoran 
Zone, its range in Arizona extends up to an altitude of at 
least 5,000 feet. 
Habits —Unknown. 
Family 15. HYDRIDE 
This family comprises a number of genera of poisonous 
snakes which are closely related to the Elapide but are high- 
ly specialized in adaptation to their marine life. Only one 
genus, with a single species, occurs in American waters. The 
tail is flattened from side to side, short and paddle-shaped. 
The head plates are large. Both jaws are toothed. The per- 
manently erect poison-fangs are near the front of the mouth, 
as in the Elapide. There are no rudiments of limbs or 
pelvis. The eyes are small. The sea-snakes all are vivipar- 
ous. Most of the species and genera are found in the tropi- 
cal or semitropical portions of the Indian and western Paci- 
fic oceans. 
