360 DR. H. GADOW ON EVOLUTION [Mar, 20, 



large- scaled collar of the var. balsas and of C convinunis occi- 

 dentalis. 



Humerus mostly with 4 large and about as many smaller rows 

 of scales, some of which jDass gradually on the elbow into those of 

 the posterior side of the forearm. 



Forearm (text-fig. 63 A-D ; 61 0). — Here prevails considerable 

 variation. It is rarely covered entirely with granules, several 

 rows being enlarged, although sometimes but slightly ; as a rule 

 more obviously so that a cluster, oi- several rows of large polygones, 

 are present ; only in one specimen, the smallest of the types, is 

 the one long row of large, transverse scutes in the var. typica. 

 But in the var. balsas large scutes are much more common. The 

 great variability, even in specimens from the same locality, is 

 shown in the table, p. 362. 



Front of forearm (text-fig. 61 A, B, D). — Mostly with three 

 complete rows of plates, rarely with only two lai-ge rows, some- 

 times with a smaller fourth lateral row. Attention may be drawn 

 to the peculiar arrangement (text-fig. 61 I) which was observed 

 in a specimen from Cuernavaca and one from the southern slope 

 of the Cajones lidge, a very good illustration of the fact that in 

 the kaleidoscopic changes of this scutellation exactly the same 

 arrangement may be hit upon "accidentally " in widely separated 

 •specimens. 



Front of tibia with 3 to 4 rows. 



Fer)%ur mostly with 7 rows, 3 of Avhich extend to the knee, as 

 is the case in C. sexlineatus and C. deppei. 



Femoral pores mostly from 16-20; cases of 23 or 24 being 

 quite exceptional. 



The males reach a great size ; specimens of 120 mm. being 

 quite common. The largest, of 132 mm., from Totolapan, is one 

 of the record specimens of Cnemidop>hori, surpassed only by two 

 specimens of C. commionis australis from Cuicatlan, likewise in 

 tlie State of Oaxaca. 



CnEMIDOPHORUS MEXICAN us, Var. TYPICA. 



Material examined : — 



I. The three type-specimens in the Berlin Museum, collected 

 by Uhde, and supposed to be from the neighbourhood of the town 

 of Oaxaca. 



II. 16 specimens collected by myself a few miles to the west of 

 Oaxaca town on oper, rather barren teri^ain, or on the slopes of 

 stony ravines with icanty scrub. 



III. 4 specim' is at Totolapan, a similar terrain, near the 

 southern foot o'' ihe Mexican plateau, in the Tierra caliente. 



Unfortunat ly all the type- specimens are young. They happen 

 to agree witli each other, and differ from those collected by 

 myself by decidedly larger scutes on the posterior side of the 

 forearm. 



Coloration. — Under parts mostly uniform pale yellowish white, 

 v/ith a reddish tinge on the hind limbs and on the throat, while 



