350 DR. H. GADow ON EVOLUTION [Mar. 20, 



breaking up into spots in the adult male." Further, there are 

 two varieties of this lizard : — " I. With rows of light spots in the 

 female ; in the male the stripes break up into round spots ; 

 known from Colima and from Coban in Guatemala." [These I 

 distinguish as C. commitnis co2)ei.—-~il.G.] "II. No spots, and 

 the bands are unbroken, resembling the young of var. I." 

 Such are said to be known from Guadalajara, Cordova, Guate- 

 mala, San Antonio. Which of the various places called Cordova 

 and San Antonio are meant, is left to our imagination. There 

 is a San Antonio in Western Yucatan ; but Cope became very 

 vague about his C. communis, as shown by the fact that in Proc. 

 Am. Phil. Soc. 1885, p. 379, he returned this kind as from 

 Matamoros, and from S. Antonio in Texas ! Concei-ning this 

 second variety, its definition is too vague ; the indifferent cha- 

 racters apply to the young of almost any C. gularis in the widest 

 sense ; but Cope at tha.t time thought that the possession of a 

 fi'enocvilar plate was a distinctive character of his G. commuiuis. 

 He partly amended this in his paper in Proc. Am. Phil. Soc. 

 xxiii. 1886, p. 283, where he managed to describe the various 

 evolutionary stages and individual variations of the true G. gularis 

 as 4 subspecies, and those of his future G. sccdaris as 2 subspecies. 

 This, again, he has partly amended in his posthumous work. The 

 synonymy has consequently become rather intricate. 



In Trans. Am. Phil. Soc. xvii. 1893. p. 47, it is stated that 

 G. communis, from Colima, " reaches a larger size than any otheis 

 of the G. gularis, and its peculiar coloration of small (or sometimes 

 large) yellow spots on a dark olive ground gives it a very distinct 

 appearance." 



Lastly, in Cope's key of his subspecies of G. gularis, p. 601 in his 

 posthumous work, G. g. communis, from " South-western Mexico," 

 is diagnosed as follows : — " Stripes broken up into lows of spots; 

 interspaces with yellow spots ; hind legs with or without yellow 

 spots ; no posteiior femoial stripe ; a fren orbital ; 5 oi' 6 iiifi-a- 

 labials ; large." 



I have examined the following few specimens, which I refer to 

 as G. communis copei, since they seem to conform most completely 

 with Cope's types. 



One specimen from Golima (text-fig. 78 E). — Throat white ; 

 scales of the large collar with bluish bases. Pai-t of imdei- parts 

 blue, with white edges to the scales. Tail blue all round. Ground- 

 colour above blue-grey, without any black bars or black spots. 

 There are remnants of six faint stripes, each broken up ixito a row 

 of white spots, and there is one row of whitish spots in each field. 

 Total number of rows of spots about 12, Thighs above and 

 behind, and root of tail, with smaller spots. 



Oiie sjjecimen from San Domingo, Ist/wius. — With many small, 

 rather irregular yellow spots on the root of the tail, thighs, rump, 

 and lower back. Further forwards these pale spots disappear 

 and faint dark spots appear in the dark brown fields, togethei- 

 with traces of the vanishing stripes 1 and 2. The region of the 



