MILLIPED GENUS CHEROKIA — HOFFMAN 235 



light stipple in figure 6. Altitudinally the variation ranges from about 

 1,500 feet at Chatooga Ridge to 4,800 feet at Walnut Creek Gap. 



Crossbands formed by lateral prolongation of the median spots are 

 characteristic of the majority of the Chcrokia population over Georgia, 

 Alabama, and a part of Tennessee. In this phase the band is widest 

 at the middorsal line and pinches somewhat at the base of the paranota. 



True crossbands, transversely parallel and rather broad, occur at 

 widely separated localities and doubtless represent the end product 

 of local specialization. In the extreme northwest, on the western 

 Highland Rim of Tennessee, occurs a form with bands almost half as 

 wide as the length of the metazonite and deep red in color. This 

 population clearly derives from adjacent forms to the southeast, 

 which are trimaculate with red or chestnut, but a good picture of the 

 situation cannot be gained at the present with the few available 

 collections from northwest Alabama. 



Of more immediate interest is the independent recurrence of a 

 yellow-banded form at two isolated places in the southern Blue Ridge. 

 One of these occupies the northwestern end of the Cowee Range in 

 Macon and Jackson counties, North Carolina. In this region, river 

 valleys do not constitute formidable barriers to gene flow, but the 

 intercalated mountain ranges afford by their height something anala- 

 gous to the effects of insular isolation, local populations normally 

 attaining greatest differentiation and stability at higher elevations. 

 The Cherokia occurring on Cowee Bald (elevation 4,800 feet) is a 

 striking animal — glossy black with broad lemon-yellow crossbands 

 and legs — and the population there seems to be a homogeneous one. 

 Cowee Bald is set off from the rest of the range by a rather low gap 

 just northeast of Franklin, North Carolina, but the development of 

 its local form is presaged by the occasional collection of similar 

 appearing individuals as far to the southeast as Highlands, North 

 Carolina. 



Snould local populations in this genus ever be considered as eligible 

 for subspecific names (a course which is avoided at the present writ- 

 ing), the Cowee population would seem at first to be an outstanding 

 contender for a name. But its claim is challenged by an identical 

 population which lias developed in Cades Cove, on the western base 

 of the Smokies in Blount County, Tennessee. In this case the 

 transition from the trimaculate population to the south is seen in a 

 collection from the southern edge of Cades Cove, containing both 

 forms and one intermediate. This banded population is, in a sense, 

 as isolated as its counterpart on Cowee Bald, for although it is geo- 

 graphically contiguous to the northeast with the narrow-bodied form 

 of the Great Smokies, it seems very unlikely that gene flow takes 

 place between them. In addition to the difference in size and pro- 



540228—60—2 



