TEIID LIZARDS OF THE GE^^US CNEMIDOPHORUS 69 



found living in districts of intermediate bionomic conditions, so that 

 now at best they are subspecies, if not local races, or, Avorse still, onl}^ 

 pattern varieties." It is significant that most of Gadow's inter- 

 lucdiatc s])ecinu'iis canic from southeastern (iuerrcro, instead of 

 from the Isthmus of Tehuantepec. These " intergrades " are not 

 geographically intermediate between the spotted eastern (/uffatus, 

 which Gadow confined to Vera Cruz, and the striped immutahilis 

 from Oaxaca, but are found isolated on the Pacific slope of Oaxaca 

 where only typical hnmrifnl>nis is theoretically expected. After the 

 examination of a large series of these lizards the writer feels that the 

 two entities under discussion should no longer stand apart. Al- 

 though certain populations do appear to be moderately well differ- 

 entiated, pattern intermediates are found in many places and in 

 addition the appearance of unicolored young in both phases makes 

 it increasingly difficult to separate one from the other. Moreover, 

 it appears that the lined phase sometimes changes into the spotted 

 one. 



A specimen typical of IranvdahRis was described as microlejyidopus 

 by Cope (1877) Avith the statement that " This form differs from the 

 typical fjuttatns in color only and may be the young. The median 

 dorsal region is, however, unspotted."' An examination of the tj'pe 

 shows it to be an 8-lined specimen, the dorsal stripes unbroken. 

 Just why iminutabilh and microlepldoinis should have been designat- 

 ed as dl^erent species in the same contribution is not apparent. 



Evidently through an oversight. Gadow (1903) described striatus 

 from the type locality of immutaljilis, citing differences from the 

 spotted guttatius. Soon after this (1906, p. 374), he listed the new 

 form in the synonymy of immutahUis. 



Diagnosis. — The ]Mexican race runner is distinguished by its large 

 maximum size and the usual presence of three supraoculars, three 

 l)arietals, granular postantebrachials and weak caudal keels. Speci- 

 mens may be unicolor, spotted or striped. If spotted, the spots are 

 usually confined to the dorsal region only. The unicolor specimens 

 are mostly young and are generally gray or blackish instead of 

 broAvnish as in gularis. The maximum number of stripes is eight. 



Examples of deppii are sometimes so close to gut fat us that separa- 

 tion is almost impossible, although usually specimens may be diagnos- 

 ed at once. Tliere are apparenth' no differences in scutellation. 

 The largest deppii seldom exceed a length of 80-85 mm. from snout 

 to anus, but the larger guttatus specimens always exceed this length 

 and the smaller ones are generally unicolor. Although there are 

 usually two distinct, lateral, light lines on each side of the base of 

 the tail in deppii, there is usually only one in guttatus, and whereas 

 the femora of deppii are often covered by distinct, rounded, light 

 spots, those of giittatiis are usually obscurely spotted or reticulated 



