Turbellarian taxonomic database
Hyman LH 1937 (citation)- Discussion of this species and confusing it with P. gracilis. She notes: 'I have had
specimens of this species from Swan's Island, Maine; it was described by Girard and Woodworth from the
vicinity of Cambridge, Massachusetts, where I also have found it; and I have taken typical specimens at New
Haven, Connecticut. Material found in a spring-fed stream near Yonkers, New York, has also proved to be P.
woodworthi and specimens sent to me from Princeton, New Jersey, through the kindness of Professor Dahlgren of
Princeton University, were either identical with New England specimens in the details of the copulatory
apparatus or differed slightly from them. The Delaware River therefore constitutes the boundary betweehn P.
gracilis and P. woodworthi with some evidence of transitional features in New Jersey material.'
Kenk R 1972 (citation)- p 44, "Northeastern parts of the U.S. north of the Delaware River and eastern Canada as
far west as Ontario."
Kenk R 1970 (citation)- p 13, 'Little is known about the ecological requirements of P. woodworthi. It is
generally taken in ponds and rivers, more rarely in cold streams and springs. The fact that it often shares
its habitat with such eurythermic species as Dugesia tigrina (Girard) and Procotyla fluviatilis Leidy
suggests that it tolerates greater temperature fluctuations that does P. gracilis.'
Ball & Reynoldson 1981 (citation)- p. 88, "The introduction of thos species has probably occurred from cocoons on equipment brought over by American scientists in search of the Loch Ness 'Monster'. It is a large and vigorous species and its spread in Britain should be monitored."
Notes from synonyms