Ticul Alvarez

“ Comparisons.—From Spermophilus spilosoma annectens (specimens from Padre and Mustang islands, Texas) , S. s. oricolus differs as follows: larger in external dimensions but smaller in cranial dimensions; postorbital constriction narrower, 13.4 (13.2-13.8) instead of 14.0 (13.5-14.7) ; rostrum slightly broader; greatest distance between posterior border of maxillary plate and squamosal arm of zygoma longer, averaging 9.9 (9.7-10.2) instead of 9.6 (9.0-10.1) ; zygomatic process of maxillary, viewed dorsolaterally above lacrimal narrower, having anterior border concave instead of almost straight ”

“ In color, specimens from the barrier beach are pale as is oricolus, but the over-all color is reddish cinnamon rather than cinnamon buff. Concerning the juncture of the zygomatic plate with the jugal, 12 of the 13 specimens studied resemble annectens in this character and one resembles oricolus. The specimens from the barrier beach may themselves represent an unnamed subspecies; more material than now is available is needed, because most of the specimens are not fully adult. ”