Occurrence of the Milliped Pachydesmus 



crassicutis incursus Chamberlin in the 



Kings Mountain Region of North Carolina 



and the Coastal Plain of South Carolina 



(Polydesmida: Xystodesmidae) 



Rowland M. Shelley 



North Carolina State Museum of Natural History, 

 P.O. Box 27647, Raleigh, North Carolina 2761 7 1 



AND 



Marianne Filka 



Department of £00 logy, North Carolina State 

 University, Raleigh, North Carolina 27607 



ABSTRACT. — The milliped Pachydesmus crassicutis incursus Chamberlin 

 is reported from specific localities in the Kings Mountain region of 

 North Carolina, the northeastern limit of the genus, and the Piedmont 

 and southern Coastal Plain of South Carolina. Males are generally 

 larger than females, and individuals of both sexes are generally darker in 

 color and larger in the Kings Mountain region than in the southern part 

 of the range. Gonopodal variation is evident in the apical portion of the 

 secondary tibiotarsus, especially in the subterminal process, which may 

 be blunt, pointed, or absent. The secondary tibiotarsus is longer than 

 the primary branch in individuals from southern South Carolina, but 

 the two structures are subequal in specimens from the Kings Mountain 

 region. 



Millipeds of the genus Pachydesmus are the largest polydesmoids in 

 North America. They occur in the southeastern states from South 

 Carolina and Tennessee to eastern Texas, but tend to be secretive and are 

 generally encountered less frequently than other xystodesmids. Hoffman 

 (1958) recognized two species: Pachydesmus clarus (Chamberlin) and P. 

 crassicutis (Wood), the latter represented by eight subspecies. The Mis- 

 sissippi River divides their ranges, with the former occurring on the 

 western side and the latter on the eastern side. The easternmost represen- 

 tative, P. crassicutis incursus Chamberlin, inhabits the foothills of Georgia 

 and South Carolina adjacent to the southeastern edge of the Blue Ridge 

 Mountains, and is known definitely from Tallulah Falls, Habersham 

 County, Georgia; and Easley, Pickens County, and Taylors, Greenville 



Adjunct Assistant Professor of Zoology, North Carolina State University. 



Brimleyana No. 1: 147-153. March 1979. 147 



