THE MILLIPED FAMILY RHISCOSOMIDIDAE 
(DIPLOPODA: CHORDEUMIDA: STRIARIOIDEA) * 
By William A. Shear 
Department of Zoology, University of Florida, 
Gainesville, Florida 32601 
Silvestri (1909) established the Family Rhiscosomididae for the 
single species Rhiscosomides miner i, from Oregon. Aside from the 
description of a second Oregon species by Chamberlin (R. josephi) 
from a female (Chamberlin, 1941), nothing further had been 
learned about the relationships or ecology of the millipeds of the 
family until my general review (Shear, 1972) of the North Ameri- 
can families of the Order Chordeumida. In that paper, I described 
a third species, R . acovescor J from California, transferred Tingupa 
monterea Chamberlin to Rhiscosomides/ and established the relation- 
ship of the Family Rhiscosomididae to the Families Caseyidae, Uro- 
chordeumidae and Striariidae. Together, these four families make 
up the Superfamily Striarioidea. 
Beginning in late 1971, I received nearly 600 unsorted Berlese 
samples from Ellen M. Benedict, of the Department of Biology, 
Portland State University, Portland, Oregon, and about 50 similar 
samples from Dr. David Malcolm, Pacific University, Forest Grove, 
Oregon. These samples were taken pursuant to studies of pseudo- 
scorpions, but also contained a large number of millipeds. The milli- 
peds from this material add enormously to our knowledge of the 
fauna of the northern Pacific coast of the United States, and I am 
extremely grateful to Mrs. Benedict and Dr. Malcolm for allowing 
me to examine them. This paper represents the first report based 
largely on the Oregon Berlese material, which now allows a more 
or less comprehensive revision of several little-known milliped fam- 
ilies. I am also grateful to Dr. Paul Arnaud, California Academy 
of Sciences, San Francisco, California, for allowing me to borrow 
that institution’s collection of unidentified millipeds. 
However, despite the rich material now available, a number of 
questions remain to be answered concerning the rhiscosomidids. 
( 1 ) Chamberlin’s species R. montereum , the southernmost known 
representative of the genus, remains unstudied, since the types (the 
only known material) are no longer in existence. It appears to be a 
species distinct from R. acovescor , of Marin County. (2) The re- 
*Manuscript received by the editor July 5, 1973 
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