132 BULLETIN 114, UNITED STATES NATIONAL MUSEUM. 



to look for it, we should be able to extend our knowledge of its 

 range. 



It is highly desirable to learn how far west it occurs in order to 

 see if there is any approach in structural characters to calligaster. 



It will undoubtedly be found farther north in Maryland, perhaps 

 even in New Jersey. 



Published records for localities not included in the list of speci- 

 mens examined are as follows: Illinois (Davis and Rice, 1883, 34), 

 undoubtedly an error; Groveton, Virginia (Ditmars, 1907, 345). 

 Furthermore Mr. Dunn reports finding examples at Warminster, 

 Norwood, Midway Mills, and Wingina, in Nelson County, and at 

 Bent Creek in Appomattox County, Virginia. 



Variation and affinities. — The study of variation in this form can 

 not be undertaken at present with any satisfaction, due to the totally 

 inadequate series of specimens available, and their unequal distri- 

 bution over the area inhabited by the species. The accompanying 

 table has been prepared as a summary of the situation as it now 

 stands. 



Summary of certain structural characteristics of rhomhomaculata. 



Region. 



Knoxville, Tennessee. . 



Alabama, Georgia, and 



Florida. 

 Southern Virginia to 



South Carolina. 

 District of Columbia 



and vicinity. 



Whole range 



Ventral 

 plates. 



202-205 

 }l97-208 

 |l96-213 

 |l91-211 



191-213 



203.5 

 202.4 

 203.7 

 200.3 

 201.5 



Dorsal 

 blotches. 



f^ 



51-55 

 50-58 

 4&-60 

 48-64 

 48-64 



W 



7.00 

 7.00 

 7.03 

 7.00 

 7.01 



8.50 

 8.50 



8.38 

 8.13 



8.29 



Tail divided by- 

 total length. 



r 0. 150 

 t .128 

 r0.127- .139 



. 121- . 148 

 . 112- . 123 

 . Ill- . 135 

 . 101- . 130 

 150 

 131 



/ .111 .] 

 \ .101- -1 



0.133 



.132 

 .118 

 .124 

 .117 

 .124 

 .119 



Caudals. 



55 

 44 

 47-52 

 4: 

 43-50 

 42-43 

 37-48 

 31-43 

 37-55 

 31-44 



Male.. 



Femalej 



Male.. 



Feraalej 



Male.. 



Female 



Male..! 



Female! 13 



Male.. 37 



Female 18 



Upon comparison with the similar table for caUigaster, it will be 

 noticed (1) that the averages are strikingly similar for everything 

 except the labials, (2) that they are, in nearly every instance, slightly 

 lower than the corresponding figures for the other form, (3) that the 

 ventrals, infralabials, and caudals reach their lowest averages at the 

 most northerly locality, and that here this form is farthest removed 

 both structurally and geographically from calligaster. 



Not only in its externally visible features of scalation, pattern, 

 and bodily proportions, but also in its penial and dental characters 

 does it demonstrate its close relationship with calligaster, and with 

 or through calligaster its near relationship to the members of the 

 getulus group. Its closest relatives, therefore, are all forms that get 



