ON VARIATION. 33 



The ground color in this form is gray, and the spots 

 are a rich brown with black borders. The belly has a 

 white ground color. 



In Fig. 3 we have the subspecies clerica, where 

 the following modifications appear. The fusion of the 

 limbs of the chevron is more complete, and the dorsal 

 spots are more expanded transversely. They extend 

 to within two or three scales of the gastrosteges, while 

 in the form trianguhis they are five scales distant. The 

 alternate spots touch the gastrosteges. This figure is 

 taken from a specimen in the Museum of the Phila- 

 delphia Academy from southern Illinois. 



In Fig. 4 we have an individual from Elmira, Illi- 

 nois, which illustrates the characters of the form col- 

 laris. Here the chevrons are distinct from the first 

 dorsal spot, whose anterior black border forms a half 

 collar on the neck. This specimen. is instructive, as 

 it displays the last connection between the chevron 

 and the first spot, in a black line on each side. This 

 is wanting in the typical collaris. 



The collar of ground color is complete in its an- 

 terior border, as well as the posterior in the form tem- 

 poralis (Fig. 5), owing to the disappearance of the 

 chevron. The transverse band on the prefrontals has 

 also disappeared. The anterior extremity of the post- 

 orbital stripe is cut off, and consists of a spot of ground 

 color. The dorsal saddle spots are wider, reaching the 

 gastrosteges, while the intermediate spots are exclu- 

 sively gastrostegal. The spots which alternate with 

 them, have fused on the middle line. Fig. 5 is from 

 a specimen from the State of Delaware. 



In subspecies doliata the postocular stripe has dis- 

 appeared, and the chevron is replaced by a black patch 

 on the parietal and temporal plates. In other respects 



