128 



BULLETIN 61, UNITED STATES NATIONAL MUSEUM. 



Ilahits and habitat relations. — Nothing is known of the habits of this 

 form, but it is significant that several specimens in the U. S. National 

 Museum, collected by F. Sumichrast, arc labeled "Alpine region," by 

 which is probably meant the pine zone surrounding the zone of grasses 

 and herbaceous forms which margins the snow fields and glaciers of 

 the simimit. Dr. W. L. Tow^r informs me that the pine zone attains 

 a maximum elevation of 13,000 or 13,500 feet. That scalans occurs 

 in this habitat is shown quite clearly by the fact that a series of speci- 

 mens in the Field Museum of Natural History were taken at an eleva- 

 tion of 13,000 feet. These are the only available notes on the habitat 

 of the form. 



Range. — All that is known of the range of scalaris is inthcated by the 

 following records: Guanajuata; Jalapa and Mount Orizaba, Yera- 











Fig. 54.— Distribution of Thamnophis scalaris, as indicated by the locality records. 



cruz; Valley of Mexico and Toluca, Mexico; Tecpam, Guatemala; 

 Talpa and Autlan, Jalisco; Oaxaco. We have examined specimens 

 from all but the last three localiiies (Boulenger, 1893, 204). (Fig. 54.) 

 Whether or not it is of general distribution in the region indicated by 

 these records can not be conjectured, as practically nothing is known of 

 its habitat relations. 



Variation. — It is highly inexpedient to attempt to draw conclusions 

 on the nature of the variations in such a small series as is here available 

 more especially since fifteen out of the nineteen specimens hail from 

 one locahty. In the accompanying table, however, we give the scutel- 

 lation and measurements of all of the specimens examined, and not- 

 withstanding the scarcity of material certain facts stand out cjuite 

 prominently. Thus, the sixteen specimens from Orizaba and Jalapa, 



