294 PROCEEDINGS OF THE NATIONAL MUSEUM vol. iie 



Comparative material examined: 



C. velox. — Arizona: apache co.: Little Colorado River (UMMZ 85054); 

 NAVAJO CO.: 1 mi. N. Winslow (UMMZ 74025); New Mexico: cateon co.: 3 

 mi. NE, Horse Springs (UCM 6095-6102); rio arkiba co.: 7 mi. N. El Rito 

 (UMMZ 69081); san juan co.: 7 mi. E. Blanco (UCM 7250-59); 43 mi. SE. 

 Bloomfield (UCM 7260-62); 1 mi. N. Chaco Canyon Nat. Mon. (UMMZ 120288); 

 Chaco Canyon Nat. Mon. (UMMZ 122915); Utah: kaxe co.: 6-7 mi. NW. 

 Kanab (UMMZ 73323-24); san juan co.: 3 mi. W. Monticello (UMMZ 121484- 

 85); Natural Bridges Nat. Mon. (UMMZ 120285). 



Eumeces multivirgatus multivirgatus Hallowell x E. in. epipleurotus 



Cope 



The taxonomic status of southwestern members of the E. multi- 

 virgatus complex recently has been discussed by Lowe (19o5c), Maslin 

 (1957), Mecham (1957), Heyl and Smith (1957), and Tanner (1957). 

 These authors are in essential agreement that E. gaigeae (=£'. m. 

 epipleurotus; see Axtell, 1961) and E. taylori are pattern variations of 

 E. multivirgatus, but then- opinions diverge as to the proper allocation 

 of the three available names. Mecham (1957, pp. 113-116) proved 

 that E. taylori is simply an allelomorphic pattern variant of E. multi- 

 virgatus; thus, there is no reason, in the interest of biosystematics, for 

 retaining E. m. taylori as a nongeographic subspecies as Lowe (1955c) 

 and Tanner (1957 p. 116) do. Maslin (1957, p. 87) and Mecham 

 (1957, p. 112) suggested that E. gaigeae represents a stage in the onto- 

 genetic pattern change of E. multivirgatus. Such loss of color 

 pattern is well documented in the E.fasciatus group but has not been 

 demonstrated effectively in the many-lined sldnks. 



A series of 25 adults and 5 juveniles of E. m. multivirgatus from the 

 Zuni region corroborates previous suggestions concerning the deriva- 

 tion of the color pattern of E. m. epipleurotus. Complete pattern 

 reduction can be observed in this variable sample and is comparable 

 to Tanner's diagrams B through D (1957, fig. 1). An adult female, 

 collected August 12, 1960, lost the mid-dorsal light stripe in 21 months 

 of captivity. 



To test possible correlation of pattern change with increasing size, 

 and presumably age, the hybrid index method of Sibley (1950, p. 112) 

 and others was adapted for present use. The characters examined 

 were middorsal light line, dorsal dark line on the first and/or second 

 scale rows, lateral hght line on the sixth and/or seventh scale rows, 

 and tail color pattern. The degree of intensity of each stripe was 

 graded per specimen on a scale of (= present, as in typical E. m. 

 multivirgatus) to 3 (—absent, as in typical E. m. epipleurotus). Tail 

 color-pattern change (from blue to blue gray mth lines, to brown 

 with lines, and ultimately to brown with lines and spots) was gi-aded 

 in like manner. By adding the character values for a specimen, a 



