Acanthocephala in North American Amphibia

Abstract

A careful search of the literature has revealed but a single instance in which Acanthocephala have been found parasitic in North American Amphibia. Stiles and Hassall (p. 352) record the occurrence of Acanthocephala in Diemyctylus viridescens, Raf. taken in Maryland by Dr. Hassall, though no determination of the species is given in the work cited. Through the courtesy of Dr. B. H. Ransom of the U. S. Bureau of Animal Industry the writer has been permitted to study these undetermined forms. The label accompanying this collection of seven worms bears the additional information that the host was taken at Franklin Falls, Baltimore, Md., in May, 1893, and that they were from the intestine. The location of the brain (Fig. 1) at the base of proboscis sheath, together with the fact that the retinacula proceed directly from the posterior end of the sheath give sufficient data for ascribing these specimens to the genus Acanthocephalus Koelr. Further the writer has determined them as belonging to the species A. ranae (Schrank). The recent work of Luhe (1912) upon variability in the number of proboscis hooks in this species has led the writer to make a study of this point in the material at hand. In forty-three specimens collected from the same locality Liihe found the number of longitudinal rows of hooks varied from thirteen to nineteen (1912, p. 297), while the number of hooks in each row varied within the limits of four and six. Some individuals had rows of four hooks