302 DR. H. GADow OX EVOLUTION [Mar. 20, 



Cnemidophorus sexlineatus Linn. 



(Text-figs. 71 A, B, C ; 62 B: 65 D ; 73 A, B.) 



Materinl examined :— 



4 from Raleigh, N. Carolina. 



3 (1 each) fi'om Pensacola, Floi'ida ; Kansas ; Duval 

 County, Texas. 



2 fx'om Bloomington, Indiana. 



3 from San Diego, California. 



•i from Sauz, north of Chihuahua (Coll. Dr. Meek). 



Definition. — 4 supra oculais. Collar composed of several rows 

 of large scales (text-fig. 65 D) ; posterior surface of forearm with 

 several rows of slightly enlarged granules (text-fig. 62 B). Under- 

 parts white ; 6 to 7 white or yellowish complete stripes on the 

 i)a.ck ; fields dark without spots (text-fig. 71 A, B, C). Size 

 distinctly small, up to 70 mm. ; an adult 5 from Sauz, with large 

 eggs, only 57 mm. 



With very wide distribution in iS^orth America ; from Maryland 

 and Delawai'e to Illinois, Kansas, and Nebraska ; southwards to 

 Florida, through Texas to Laredo, thence to Chihuahua, Ai-izona, 

 and into Southern California. 



Linne's types came from Chai-leston, S. Carolina ; Edit. xiii. 

 p. 364 : " Corpus supra utrinque lineis 3 albis angustis et totidem 

 nigris alternis. Dorsum lineis 3 mediis inteijectum, canescens 

 quasi ex duabus lineis albidis. Ruga" duo sub collo."' 



Supraoculars 4 ; the posterior is sepai'ated from the paiietals by 

 one or more rows of granules, unless it is almost in contact 

 with the parietals. Of the four Raleigh specimens only tlie 

 largest has 4/4 complete supraoculars ! In one of 68 mm. only 

 3/3 ; in the other of 68 mm. (text-fig. 71 A) the posterior is 

 absent on the left side, on the right it is reduced to a large 

 granule, and the anterior scute is broken up into several. The 

 58 mm. specimen has only 3/3, due to loss of the posterior scutes, 

 but the antei'ior pair is broken up into several. 



Frenocvdar plate variable. In two Raleigh specimens present, 

 in one absent on both sides, in one present on the left side only. 

 Absent in all the four Sauz specimens. 



Collar (text-fig. 65 D). — Accoi-ding to Cope, " scales of collar- 

 larger, in few rows, the largest forming the lower." In i-eality the 

 collar of C. sexlineatus is variable and closely approaches that of 

 the C. deppei- group. Instead of the posterior edge being formed 

 by a row of lai-ge scales, it is in many cases, at least in the centre, 

 composed of granules only ; or theie are numerous granules 

 interspersed between the scales of the edge. The large scales 

 themselves often deci'ease in size rapidly towards the sides. Cope's 

 figure is much more to the point than his desci-iption. The 

 strongest collar, with an edge of large scales and but few or no 

 granules, I find in the two San Diego specimens. 



Humerus with 5 to 7 rows of scales, of which the first 2, 3, or 

 4 are considerably larger than the rest. 



