55 
Genus Scytonotus 
inornatus insulanus bergrothi simplex columbianus piger granulatus virginicus australis 
Fig. 34. Hypothesized relationships in Scytonotus. 
Ridge endemics, which rather than being old forms relegated to 
relict statuses and restricted distributions in the Appalachians as sug- 
gested by Hoffman (1969), are really young, derivative entities. The 
absence of S. granulatus from the Blue Ridge suggests displace- 
ment by the endemics, and future displacement could occur in sur- 
rounding areas, as they expand their ranges. This process has already 
begun in the south, as S. australis , probably the oldest endemic, 
has spread beyond the Blue Ridge escarpment and apparently eradi- 
cated S. granulatus from the western periphery of the Piedmont 
Plateau in the Carolinas and north Georgia. 
ACKNOWLEDGMENTS — I am indebted to the National Science 
Foundation (NSF) and the National Geographic Society (NGS) for 
supporting my field expeditions across North America for the past 
15 years, which have produced numerous samples of Scytonotus. 
Pertinent grant numbers are DEB 7702596 and 8200556 for NSF, 
and 3871-88 and 4495-91 for NGS. Laboratory studies of the col- 
lections took place in January 1992, when I was working at the 
NMNH on an NSF Mid-Career Fellowship. Access to the types of 
P. amandus and 5. piger, bergrothi, orthodox, and simplex, and to 
nontypical material at the NMNH was courtesy of J. A. Coddington; 
the type of S. columbianus and other specimens at the MCZ were 
loaned by H. W. Levi; and the types of S. insulanus and pallidus 
(NMV) were provided by J. Gruber. Material in the following 
repositories was loaned by the indicated curator or collection man- 
ager: AMNH, N. I. Platnick; ANSP, D. Azuma; BMNH, P. Hillyard; 
BYU, R. W. Baumann; CADFA, A. R. Hardy; CAS, W. J. Pulawski; 
