The Amphibians and Reptiles of Sinaloa, Mexico - Smithsonian ...

168 UNIVERSITY OF KANSAS PUBLS., MUS. NAT. HIST.
northern Sinaloa and eight scale rows in southern Sinaloa. Although
snakes with complete blotches occur almost throughout the
range of the species, there are none with four or more rows separating
blotches and ventrals north of Guamuchil.
Sinaloan specimens of this species are red or red-orange in dorsal
ground color, with black blotches and a white venter. The color of
a living specimen from Sonera (LACM 6834 from 15 miles south
of Santa Ana) is as follows: black blotches have light centers
laterally and are separated from each other by pale cream interspaces
middorsally, to give the appearance of an interrupted middorsal
stripe; ground color laterally and between black blotches
orange; first two scale rows above ventrals white; lateral interspaces
with one or two black-tipped scales; head with orange border
around black interorbital spot and anterior part of nuchal collar;
snout white; ventrals and subcaudals white, some subcaudals with
black spots.
The geographic irregularity of variation in some characteristics
and the clinal nature of the variation in other characteristics does
not justify the recognition of subspecies. Therefore, we place
Gyalopion quadrangularis desertorum in the synonymy of G. quadrangularis.
Most specimens of this small nocturnal snake were taken on the
road at night. None were collected when the air temperature was
below 27°C, and the majority were active at night at an air temperature
between 28° and 29°C. A specimen from near Terreros was
found beneath a rock. Another was found after a morning rain on
a floating stick in a water-filled irrigation ditch at Villa Union.
Greer (1966:372) reported the species to be oviparous.
Distribution in Sinaloa.—Throughout the state from sea level to
1220 meters elevation. See Fig. 66.
Specimens examined.—Ahome (* LACM 8651-53); 13 mi. ESE Badiiaguato,
800 ft. (• KU 83405); 38.1 mi. S Coyotitan [San Ignacio tumoff ] ( " LACM
6838); 8.7 ml. N Culiacan (" LACM 6844); 17.3 mi. N Culiacan (CSCLB 1402 h
31,2 mi. N Culiacan (" LACM 6845); 32.5 mi, N Culiacan ("LACM 6846);
43 mi. N Culiacan ( i LACM 6847); 46.4 mi. N Culiacan ("LACM 6848);
63 mi. N Culiacan ('KU 73505); 19 km. SSE Culiacan ('KU 73517); 18
mi. S. Culiacan ("LACM 6853); 50.5 mi. S Culiacan (FAS 13776); 30 mi.
W Culiacan ("ASDM 1791); ElCajon, 1700 ft ("KU 93492); El Dorado
( • AMNH 79916); 17.3 mi. S Escuinapa (CSCLB 1410); 34 mi. S Escuinapa
(CSCLB 1404); 0.8 mi. S Guamuchil ("LACM 6857); 6.5 mi. S Guamuchil
("LACM 6855); 3.1 mi. E La Cmz ("LACM 6835); 1.5 mi. N Los Moehis
(*FAS 11653); 8 mi. NE Los Moehis ("KU 73506); 2.9 mi. N Mazatlan
("LACM 6836); 3 mi. N Mazatlan ("MCZ 61415); 5-10 mi. N Mazatlan
("LACM 8654); 9.3 mi. N Mazatlan (CSCLB 1403); 9.6 mi. N Mazatlan
(CSCLB 1412); 10.6 mi. N Mazatlan (CSCLB 1409); 11.5 mi. N Mazatlan
("LACM 6839); 12 mi. N Mazatlan (JFC 62:46); 13.3 mi. N Mazatlan