46 DEPARTMENT OF AGRICULTURE


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 Figure 31.-The awl nematode, Dolichodorus heterocephalus, Cobb, an interest-
ing type of root parasitic nematode because of its awl-shaped, long, buccal stylet and
the trilobed bursa in the male. A. Anterior end; dsl oe gl, outlet of dorsal oesopha-
geal gland; x 500. B. Cross section through middle region of body to show the
structure of the lateral fields consisting of two longitudinal bands separated by three
longitudinal grooves; gr lat, grooves in lateral field; x 500. C. Tail end of 9 seen
dorsally; anus; phas, phasmid; X 500. D. Tail end of 8 seen dorsally to show the
trilobed bursa; phas, phasmid; sp, spicula, gub, gubernaculum; x 500. The speci-
mens of this parasite here partly sketched were collected by A. L. Taylor on celery
roots near Sanford, Fla. in December 1943. In the "Plant Disease Reporter" of
December 15, 1943, p. 707 they were recorded as a species of a genus closely related
to Paratylenchus; however, it is now certain that Dolichodorus represents a separate
subfamily not directly related to Paratylenchus.