Studies on Three New Genera and some Little-Known Species of the Nematode Family Protostrongylidæ Leiper, 1926

Abstract

The classification of the nematodes occurring in the lungs (and related forms) of land mammals has always been one of considerable difficulty, in large part because of the existing very inadequate descriptions of many of the commoner forms. Most systematic helminthologists have followed and amplified the classification adopted by Railliet and Henry in 1907, a system which divided these nematodes into three main groups — those found in the blood-stream (Hæmostrongylus); those found in the larger bronchi (Dictyocaulus, Metastrongylus and Crenosoma); and those found in the minute bronchi and alveoli (Synthetocaulus). While the first two groups contain four well-defined zoological species, an examination of the forms included in the genus Synthetocaulus shews that it consists of a heterogeneous collection of species, which, although possessing a common habitat, are by no means so closely related as has been supposed, and, indeed, belong to several different genera.