their dorsal
stripes were reddish orange, and markings on the dorsolateral area
were pale yellow rather than red. Specimens from the Texas Panhandle,
from Hemphill County (Brown, 1950:207) and nine miles east of Stinnet,
Hutchison County (Fouquette and Lindsay, 1955:417) likewise are most
nearly like _annectens_ judging from the authors' descriptions. The
specimens from nine miles east of Stinnet averaged large; the two
largest would have attained or slightly exceeded four feet in length
if they had had complete tails. No _sirtalis_ so long as four feet has
been recorded elsewhere.

Records are lacking from the drainages of the Republican, North
Canadian, Brazos and Colorado River drainages in the High Plains, but
possibly isolated populations occur in some of these also. The only
record from the Pecos River drainage is that of Bundy (1951:314) from
Wade's Swamp near Artesia, Eddy County, New Mexico. This locality
is separated by some 140 miles from any other known station of
occurrence.

From extreme southern Colorado south across New Mexico to the Mexican
border _T. sirtalis_ occurs in continuous or nearly continuous
populations in the Rio Grande Valley, and has been recorded from many
localities. It has been recorded from relatively few localities of
tributary streams (Los Pinos, Abiqui, Santa Fe) all near the main
valley. There is one record from the Ocate River, a headwaters
tributary of the Canadian River, in the Sangre de Cristo
Mountains near other localities in the Rio Grande drainage. The
southwestern-most known locality of occurrence is Casas Grandes in the
Mexican state of Chihuahua some 130 miles southwest of El Paso, Texas,
and near the Continental Divide. The Rio Casas Grandes must have once
been a tributary of the Rio Grande, but now its desert drainage basin
is isolated.

RE-DESCRIPTION OF A SUBSPECIES FROM NEW MEXICO

Most specimens of a population of _sirtalis_ occurring in New Mexico
are recognizably different from most specimens of other populations.
This New Mexican population is therefore here recognized as a distinct
subspecies:

THAMNOPHIS SIRTALIS ORNATA Baird

_Eutaenia ornata_ Baird, 1859:16.
_Eutaenia sirtalis dorsalis_ Cope, 1900:1076.
_Thamnophis sirtalis parietalis_ (part) Van Denburgh, 1924:222.

_Type._--U. S. Nat. Mus. No. 960, obtained at El Paso, Texas,
at some time in the eighteen fifties by Col. J. D. Graham.

_Range._--Rio Grande and vicinity, from