134 



BULLETIN 114, UNITED STATES NATIONAL MUSEUM. 



We may therefore summarize the situation with regard to rhom- 

 homaculata by considering it a derivative of calligaster by (1) a 

 shortening and strengthening of the head, developed in response 

 to burrowing habits, and particularly noticeable in the shape of the 

 snout; (2) a reduction of one in the number of infralabials, correlated 

 with the shortening of the head; (3) an average reduction of one tooth 

 in the maxillary, palatine, and mandibular series, and of two in the 

 pterygoid series; (4) a reduction in number of scale rows, amounting 

 to about two on each side of the body; (5) a slight reduction in 

 numbers of ventrals and caudals, and, correlated with the last, a 

 decrease in the proportionate tail length; (6) reduction and fading 

 of the pattern; and (7) a slight decrease in body length and girth. 



Scale formulae of rhombomaculata. 



Locality. 



21-23-21-19 



21-19 



19-21-19 



19-21-19-17- 

 21-19-17 



Male. 



Fe- 

 male. 



Male. 



Fe- 

 male, 



Male. 



Fe- 

 male. 



Male. 



Fe- 

 male. 



District of Columbia and vi- 

 cinity 



2 

 1 



4 

 3 



10 



11 



2 

 1 



7' 



3 







4 



3 



1 

 1 





Southern Virginia to South 

 Carolina . 





Georgia, Florida, and Ala- 

 bama 



2 









Tennessee 



























1 



Total 



3 



7 



24 



9 



3 



2 



9 









Total number of males, 39. 

 Total number of females, 18. 



