118 



BULLETIN 114, UNITED STATES NATIONAL MUSEUM. 



extends thus forward to between the eyes, where the forks may 

 unite again. From behind each eye a long black-bordered brown 

 band about two scales wide extends backward on top of the neck. 

 From the eye to the angle of the mouth there is a narrow dark band. 

 Thus there is a strip of the ground color from the upper postocular 

 to the last supralabial. The other head and throat plates are mostly 

 light-colored. The belly may be faintly or heavil}^ checked with 



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Fig. 39.— Typical pattern oif Lampropeltis calligaster (U.S.N.M. no. 1593, cotype of Ophibolus 



EVANSII KENNICOTT FROM CENTRAL ILLINOIS). ABOUT 1| X NAT. SIZE 



small quadrate brownish or yellowish blotches, or nearly immaculate 

 except for the ends of the ventrals. 



This pattern is well defined in 3^oung individuals, but in many 

 adults the markings, particularly of the head, lose their distinctness 

 and become greatly obscured by a darkening of the ground color. 

 Such darkening appears to be accompanied by an alternate length- 

 wise iightening and intensification of pigment, producing a rather 

 prominently striped effect (fig. 40). Throughout the middorsal 

 line there is a light stripe; bordering this on either side is a dark 

 band which passes through the lower portions of the dorsal blotches. 

 Below this, and between the dorsal and lateral series, is a light band; 

 then below this last and passmg through the upper lateral series of 

 blotches is another dark band. The two or three lowest rows of 



