12 
Rowland M. Shelley 
S. virginicus (Figs. 24, 26); and is expanded with one or two mar- 
ginal teeth in S. granulatus (Fig. 22). The most intricate structure 
occurs in S. simplex , where the lamina expands basally into a lightly 
serrate lobe, narrows at midlength, and possesses a short spur around 
2/3 length (Fig. 16). 
Genus Scytonotus Koch 
Scytonotus Koch, 1847:57. Bollman 1893:122,141-142. Cook and Cook, 
1894:233-235. Cook, 1904:61. Williams and Hefner, 1928:111. 
Attems, 1898:255-256; 1931:144-145; 1940:155. Hoffman, 1950^:219- 
250; 19626:242; 1979:173. Causey, 1955:22. Chamberlin and 
Hoffman, 1958:72. Jeekel: 1971:351. Kevan, 1983:2969. 
Lasiolathus Loomis, 1943:318-319. Jeekel, 1971:334. 
Type species — Of Scytonotus , S. scabricollis Koch, by subse- 
quent designation of Bollman (1893). Hoffman (19626) states that 
designation was by Chamberlin and Hoffman (1958), but as noted 
by Jeekel (1971), it actually dates to Bollman (1893:151). Of Lasiolathus , 
L. virginicus Loomis, by original designation. 
Diagnosis — Small polydesmids with four to five rows of rounded, 
setose tubercles dorsally on metatergites; adults with 19 segments; 
dorsum moderately convex; paranotal margins shallowly notched or 
deeply dentate, those of segments 5-9 of females of most species 
vestigial or absent; tibiae of legs 13-20/22 of males of most spe- 
cies swollen ventrad and with variable, elongate, subterminal lobes 
on anterior and/or caudal margins; telopodite of male gonopod with 
or without one or two barbed, aciculate projections proximally on 
medial surface, with elongate tibiotarsus arising basally anterior to 
endomerite, latter with basal pulvillus on caudal surface and vari- 
ably dentate medial, distal, and lateral laminas; prostatic groove in- 
ternal, with distal loop, opening at pulvillus. 
Distribution — Occurring in four separate faunal regions, one east 
and three west of the Continental Divide (Fig. 1). In the East, 
Scytonotus covers a large, continuous area east of the Central Plains 
extending from near Sault Ste. Marie, Ontario, and Trois Rivieres, 
Quebec, to southcentral South Carolina, north Georgia, and north- 
eastern Arkansas; east-west, this area spreads from eastern Vermont, 
coastal Virginia, and the Outer Banks of North Carolina to eastern 
Kansas and Nebraska. In the West, Scytonotus occurs along the 
Pacific Coast and in two areas in the interior. The coastal area 
extends from Yakutat Bay, Alaska, to Marin and San Joaquin coun- 
ties, California, extending inland to the eastern slope of the Cas- 
cade Mountains in Oregon and Washington, and includes all interven- 
ing offshore islands in British Columbia and Alaska except the Queen 
