The Chonaphini, a Biogeographically Significant 



Milliped Tribe in Eastern and Western North America 



(Polydesmida: Xystodesmidae) 



Rowland M. Shelley 



North Carolina State Museum of Natural Sciences 



P.O. Box 29555 



Raleigh, North Carolina 27626-0555 



ABSTRACT— The Chonaphini, the only Nearctic xystodesmid tribe 

 represented in both the eastern and western faunal regions, is 

 the only tribe in the family in which the prefemoral process 

 is typically more complex and of greater taxonomic utility than 

 the acropodite. The latter structure varies from narrowly blade- 

 like to acicular, and excepting Montaphe paraphoena, n.sp., 

 lacks secondary projections. The prefemoral process, however, 

 is often elaborate with secondary structures arising from the 

 stem. Six genera, three monotypic, and twelve species com- 

 prise the tribe, with Semionellus Chamberlin and S. placidus 

 (Wood) inhabiting four areas in the eastern United States from 

 southeastern Minnesota to westcentral Virginia. The other taxa 

 occur west of the Continental Divide from Montana to north- 

 central California and Vancouver Island, Canada. Chonaphe Cook 

 is represented by two new and two established species in 

 the United States, C. evexa and schizoterminalis, and C. 

 remissa Chamberlin and armata (Harger). Chonaphe cygneia 

 and patriotica, both authored by Chamberlin, and C. serratus 

 Loomis and Schmitt are placed in synonymy under C armata. 

 Montaphe elrodi (Chamberlin), the dominant xystodesmid from 

 eastern Washington to western Montana, is projected to occur 

 in the southern extremity of central British Columbia adjacent 

 to Idaho and northeastern Washington. Metaxycheir Buckett and 

 Gardner and Tubaphe Causey are monotypic, M. prolata Buckett 

 and Gardner occurring in eastern Washington and the adjoin- 

 ing part of northern Idaho, and the subcylindrical T. levii Causey 

 occurring in wet rainforests of the Olympic Mountains and the 

 southwestern corner of Vancouver Island. Selenocheir n. gen., 

 characterized by a short prefemoral process less than half as 

 long as the acropodite, consists of three new species ranging 

 from southwestern Oregon to the northern California coast and 

 the northern Sierra Nevada Mountains. Modern descriptions and 

 illustrations are presented for all tribal taxa along with keys 

 to genera and to the species of Chonaphe and Selenocheir. 



Brimleyana 20:111-200, June 1994 111 



