130 Rowland M. Shelley 



thickened irregular, convoluted projection on dorsal side at 3/4 length 

 or with angular ridge or flange, stem either broadly rounded apically 

 and with inturned lateral subapical lobe, or deeply divided with narrow 

 lateral and broad medial terminations of subequal length, or with 

 suggestion of division and with lateral side either bent strongly dorsad 

 and transversely to stem, or not bent and with laminate, coaxial projection 

 on dorsal side, or expanding distad and leaning over stem. Acropodite 

 acicular, arising on caudal or caudolateral sides of prefemur, looping 

 around prefemoral process and curling onto shelf, apically acuminate. 

 Prostatic groove arising in pit in prefemur, extending along medial 

 face of latter onto acropodite, running generally along inner surface 

 of loop to apical opening. 



Cyphopodal aperture broad, encircling 2nd legs, sides and caudal 

 margin elevated above metazonal surface. Cyphopods in situ with 

 valves oriented transversely, common surface visible in aperture. Valves 

 variable in size, subequal, lightly to moderately hirsute, medial corners 

 extending ventrad into variable lobes, subtending central depressions. 

 Receptacle small to moderately large, hirsute, or with variable numbers 

 of hairs arising from ventral margins, either cupped around valves or 

 flat and inconspicuous. Operculum relatively large, located laterad to 

 valves, with numerous long hairs. 



Distribution — Occurring in five segregated areas in the northwestern 

 United States as follows: Coos County, Oregon; Grant and Umatilla 

 counties, Oregon; Benton County, Oregon, to Mason and Chelan counties, 

 Washington; and Stevens and Whitman counties, Washington, to Missoula 

 County, Montana. This total area covers about 468 mi (753 km) in 

 the east-west dimension and 351 mi (565 km) in the north-south, and 

 encompasses parts of the Northern Rocky Mountains, Columbia Plateau, 

 Sierra Cascade, and Pacific Border Physiographic Provinces. 



Species — Four are known; more may occur in isolated pockets 

 within the generic range. 



Key to Species of Chonaphe (based on adult males) 



1. Prefemoral process with broad, thickened, convoluted projection 



from dorsal surface distal to shelf (Figs. 5-6, 11-12) 2 



Prefemoral process with angular ridge or expanded flap on dorsal 

 surface distal to shelf (Figs. 16, 18, 22-23) 3 



2. Apical margin of prefemoral process with lateral side acuminate, 



bent abruptly dorsad, lying transverse to axis (Figs. 4-6); 

 Stevens and Chelan to Yakima counties, Washington; 

 Multnomah to Benton and Umatilla to Grant counties, Oregon; 

 and Sanders County, Montana, to Kootenai and Idaho 



