154 BULLETIN" 15 4, UNITED STATES NATIOISrAL MUSEUM 



luid the latter is more or less characteristic of tessellatus every- 

 where. Neither has been found to be a reliable diagnostic feature, 

 however, since too much variation exists in both. In spite of its 

 weak diagnosis, this species was given recognition by general work- 

 ers until the event of Stejneger and Barbour's check list in 1917. 

 Baird and Girard (18r)2d, p. 338) wrote in their section of Stans- 

 bury's report as follows : "• AVe have no doubt that the lizard referred 

 to in Long's expedition, under the name of Ameiva tesselata, will 

 come under this genus, and be closely allied to our species, tigris. 

 No specimen of this {tessellatus) being extant at the present time 

 in any knoAvn collection, a direct comparison * * * is not 

 possible." And later, Baird (1851), j). 18), in re])orting on a s])eci- 

 meii collected in tlie Sah I^ake Basin of Utali, was foiccd to say 

 that "■ The s])ecimen a])pears more nearly I'efei-able to this long h)st 

 species of Say {CneDiidopItoriis trssdJatKs) than to any other, al- 

 though closely i-elated to 0. tigris.'''' In 1875 Cope gave recognition 

 to tigris in his check list, and while Yarrow and Henshaw (1878, 

 p. 1(»41) expressed the belief that tessellatus and tigris should be 

 united, they followed Coi)e in giving (iiem practical recognition as 

 distinct forms. 



An examination of the type of tigris shows it to be something like 

 those of tiwirmoratus and undulatus (or //iioulus) in color pattern, 

 rather than like the many more l>rownisli specimens that have been 

 recentW collected in TTtah. Therefore, it probably came from the 

 higher, more mountainous, less sandy levels. The tail is very light 

 brown at the tip, almost salmon in fact, a condition that almost 

 suggests ruhidus of Lower California. 



Apparently the first attempt to give critical thought to the ques- 

 tion of the value of tigris as a specific name Avas that of Stejneger 

 (1893, p. 198), who wrote the following: "Owing to the fact that 

 nearly the entire collection of North American Cnemidophori are 

 inaccessible to me at the present writing, I have been unable to settle 

 the question as to the proper name of the present species to my own 

 satisfaction. It may be that C. tigris is only a synonym pure and 

 simple of G. tessellatus (Say) or they may be trinomially sei^arable. 

 I have therefore retained the name C. tigris, as the specimens before 

 me agree perfectly with the type of the latter." After considerable 

 and increasing vai'iation in the designation used for tessellatus had 

 been displayed, Stejneger and Barbour (1917) merely listed the Great 

 liasin form as C. tessellatiis t^'ssellafus, thus submerging tigris, and 

 since that time their iiouiciicImI iirc li:is liccn generally Mccepted by 

 working herpetologists. 



The systematic notes on the remaining species are presented below, 

 in two series according to the general type of habitat that they 

 represent. The first of these inhabits tlie lower levels, particularly 



