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

190 UNIVERSITY OF KANSAS PUBLS., MUS. NAT. HIST.
midbody are 19 in nine specimens and 20 in one; 19-22 at the neck,
and 16, 17 or 19 at the vent. The supralabials are 6-6 in three, 6-5
in one, 6-7 in one, and 7-7 in three (excluding KU 73602, 73604);
infralabials are 7-7 in one, 8-8 in two, 8-9 in one, 9-7 in one, 9-9
in one and 10-9 in one (excluding KU 73601-02, 73604). The preoculars
are either two or three, postoculars two or three (four in
KU 73603), and suboculars 2 to 4. The temporals are numerous
(6-12) and highly variable.
Dark pigment in the lateral interspaces is absent, or present as
indistinct clumps; all dorsal blotches, except the anterior first or
second, have dark edges. The interorbital band barely touches the
parietals in a snake from northern Sinaloa (KU 73601); a specimen
from near Guamuchil (KU 73607) has a distinct extention of the
band to include part of the parietals. Six specimens from south of
Guannichil to about 24 kilometers north of Mazatlan have above one
half or more of the parietals included in the interorbital band. One
specimen (KU 73602) from 10 kilometers north of Mazatlan has
the band barely including the parietals. A specimen from near
Piaxtla has a second black band that crosses the parietals posterior
to the interorbital band; the interorbital band and parietal band are
connected laterally.
The ventral counts of the males, arranged in sequence from south
to north, are 160, 163, 164, 158, 148, 156, 155, and 151. The numbers
of body blotches for both sexes from south to north are 10, 13,
14, 12, 12, 14, 18, 15, 11, and 11. Four specimens, from localities in
northern and southern Sinaloa, have dorsal bands that are more
than twice the length of the interspaces and in five specimens the
dorsal bands are distinctly less than twice the width of the interspaces.
None of the characteristics used by Shannon and Humphrey to
distinguish P. b. klauberi (1959a: 145) from P. b. fortitus is consistant
in the Sinaloan specimens at hand. The variation in the number of
ventrals, extent of the interorbital band, frontal width/frontal length,
and the number of body blotches appear to be clinal for P. browni
from Sinaloa and therefore casts doubt on the validity of P. b.
klauberi. We use the binomial rather than attempting to allocate
specimens from Sinaloa to either of the subspecies fortitus or
klauberi. Phyllorhynchus browni is presently being studied by
H. W. Campbell and the second author.
Nearly all specimens were collected at night on the road.
Distribution in Sinaloa.—Vhyllorhynchus browni has been re-