outhernmost examples of _Crotalus basiliscus_ (_Crotalus
basiliscus oaxacus_ from Oaxaca) have 172-175 ventrals and 21 caudals
(Gloyd, 1948).

In Michoacan _Crotalus basiliscus basiliscus_ has been found in arid
habitats on the coast, in the Tepalcatepec Valley, and in the lower
parts of the Sierra de Coalcoman. All specimens are from localities
below 1070 meters in elevation.

~Crotalus durissus culminatus~ Klauber

_Crotalus durissus culminatus_ Klauber, Bull. Zool. Soc. San
Diego, 26:65, August 8, 1952.--El Sabino, Michoacan, Mexico.

El Sabino (18).

These specimens are part of the type series and were collected by Hobart
M. Smith near the upper limits of the arid scrub forest at an elevation
of about 1050 meters on the lower slopes of the Cordillera Volcanica at
the northern edge of the Tepalcatepec Valley. They were discussed in
detail by Klauber (1952:66-70).

~Crotalus intermedius intermedius~ Troschel

_Crotalus intermedius_ Troschel, _in_ von Mueller, Reisen in
Vereiningten Staaten, Canada und Mexico, vol. 3, p. 613,
1865.--Type locality unknown.

_Crotalus intermedius intermedius_, Klauber, Bull. Zool.
Soc. San Diego, 26:9, August 8, 1952.

Cerro Tancitaro.

The one specimen is from the pine forests on the Cordillera Volcanica.
At the present time this species is known from scattered localities in
west-central Veracruz, Oaxaca, Michoacan, and as _Crotalus intermedius
omiltemanus_ in Central Guerrero. Apparently it is restricted to montane
environments.

~Crotalus molossus nigrescens~ Gloyd

_Crotalus molossus nigrescens_ Gloyd, Occ. Pap. Mus. Zool.
Univ. Michigan, 325:2, January 28, 1936.--Four miles west of
La Colorada, Zacatecas, Mexico.

Carapan; Los Conejos; Patzcuaro; Tacicuaro (5).

In Michoacan this species has been found in pine forests between 1550
and 2300 meters in the Cordillera Volcanica. I expected to find it in
the Sierra de Coalcoman, but inquiries among the natives living in the
pine forests of that mountain range revealed that the people there have
no knowledge of a large species of rattlesnake.

~Crotalus polystictus~ (Cope)

_Caudisonia polysticta_ Cope, Proc. Acad. Nat. Sci.
Philadelphia, 17:191, December 26, 1865.--Tableland of
Mexico. Type locality restricted to Tupataro, Guanajuata,
Mexico, by Smith and Taylor (1950a:330).

_Crotalus polystictus_ Cope, _in_ Yarrow, W