126 Rowland M. Shelley 



cleft; acropodite usually simple and unmodified, acicular to narrowly 

 blade-like, either circumscribing variably broad arc, with or without 

 abrupt distal curvature change, bending anteriad at right angle proximally 

 and curving broadly distad, or looping around prefemoral process and 

 inserting on shelf on latter; cyphopods oriented transversely in aperture, 

 with or without prolongations of medial valvular corners and variable 

 central cavities, receptacles alate or flattened, hirsute with variable 

 numbers of long hairs arising primarily from ventral margins. 



Distribution — Occurring in parts of western North America and 

 the eastern United States east of the Central Plains from southeastern 

 Minnesota to the Blue Ridge Province of northern Virginia. Mapping 

 the available museum records reveals that the range is divided into 7 

 separate areas (Fig. 1): along the Pacific Coast in the southwestern 

 corner of Vancouver Island, British Columbia; from the Olympic Penin- 

 sula of Washington to the northern coast of California and the central 

 Sierra Nevada Mountains, extending eastward across the Cascade Moun- 

 tains in Washington to the western fringe of the Columbia Plateau 

 Physiographic Province; from northcentral Oregon and eastern Washing- 

 ton to western Montana and Idaho north of the Salmon River, probably 

 extending just across the International Border into southern British 

 Columbia between Rossland and Creston; from southeastern Minnesota 

 to southeastern Wisconsin; from the central lower peninsula of Michigan 

 through western Ohio to western Indiana; a single site in southeastern 

 Ohio near the Ohio River; and from western Maryland through eastern 

 West Virginia to the Blue Ridge Province of westcentral Virginia, 

 terminating in Shenandoah National Park. 



Remarks — The anatomical diversity in this diplopod assemblage 

 presents formidable obstacles to formulating a tribal diagnosis, as 

 several key features have exceptions. The gonopodal apertures are 

 large and expanded caudad in all chonaphines except C. evexa, T. 

 levii, and Selenocheir sinuata; T. levii and the species of Selenocheir 

 are the only representatives lacking a sternal remnant; Montaphe para- 

 phoena is the only chonaphine lacking an acicular to narrowly blade- 

 like acropodite and the only one with the gonosternum lacking lateral 

 lobes; the species of Selenocheir are the only ones with short prefemoral 

 processes; and Metaxycheir prolata is the only component with a 

 long prefemoral process that lacks modifications. To my knowledge 

 the Chonaphini is the only xystodesmid tribe in which the presence or 

 absence of a sternum is not constant, but the narrow aperture of 

 Tubaphe is shared with C. evexa and S. sinuata; the caudally extended 

 apertures of S. arcuata and S. directa are shared with other chonaphines; 

 and the barbules on the prefemoral process of T. levii are shared with 



