ON VARIATION. 35 



this form is more like the form collaris. The dorsal 

 saddle spots are separated by a row or two of scales 

 from the gastrosteges, and their alternating spots are 

 partly on the scales. The ground color in this form, 

 as in the teftipoi-alis, approaches red. Tin's is the form 

 of the tier of states between latitude 40" and the Gulf 

 States. 



The subspecies syspila is represented in Fig. 8. 

 The head pattern is like that of doliata with the black 

 patch more or less reduced — in the specimen figured 

 being represented by a cross stripe. The dorsal saddle 

 spots are more expanded than in any form yet encoun- 

 tered, their lateral borders being completed below the 

 scales and entirely on the gastrosteges. The alternate 

 spots now meet and fuse on the middle line of the ab- 

 domen, and the second series of alternating spots has 

 disappeared. This is distinctively a southern form, 

 extending west to central Oklahoma. 



The dorsal saddles are so far extended in the next 

 subspecies, parallela, as to form two parallel stripes 

 with a narrow strip of ground color between, on the 

 middle line of the abdomen. The alternating spots 

 have disappeared. In the specimen figured, which is 

 from Florida, and is in the United States National 

 Museum, the supraocular spots seen in temporalis, are 

 indicated. The ground color is red. Black begins to 

 appear on the head. 



From the form syspila two types of color modifica- 

 tion may be traced. One of these brings the borders 

 of the saddle spots together on the median line, form- 

 ing a median black stripe ; this is the subspecies atmu- 

 lata, which belongs to western Texas and the adjacent 

 parts of Mexico. The top of the head is black (Fig. 

 10). In the other, the Lateral borders of the saddle 



