578 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.58. 



In order, if possible, to clear up the existing doubt. Dr. B. H. Ransom 

 suggested that I make a study of the Nematodirus material available 

 in the Helminthological Collections of the United States National 

 Museum. The results indicate that there exist no such clear differ- 

 ences between N. spathiger and N. filicoUis as indicated by Railliet, 

 and furthermore four other forms, not previously described, were 

 found to be present. 



MATERIAL AND METHODS. 



In addition to the abundant material collected in the United States 

 there were available for study specimens of both N. spathiger and N. 

 fHicolUs received from Railliet, and mounted specimens of Nemato- 

 dirus collected by O. Schnyder from cattle in Switzerland. The mate- 

 rial collected by Railliet from a dromedary at Alfort, France, identi- 

 fied by him as Stro7igylus spathiger^ and submitted to the Bureau of 

 Animal Industry in 1896 (U.S.N.M. Helminthological Collections, No. 

 2760), contains three males and a number of females of N. spathiger., 

 and four males and three females of a new species resembling N. 

 77iauritanicus, described by Maupas and Seurat (1912), also from a 

 dromedary. The material collected by Railliet from Ovis aries in 

 France (U.S.N.M. Helminthological Collections, No. 4027) and 

 identified by him as Strongylus filicoUis contains three males of N. 

 filicoUis, one male of N. spathiger, and several females which may be 

 either. The specimens from Schnyder (U.S.N.M. Helminthological 

 Collections, Nos. 15728 and 15739) are different from any others ex- 

 amined. The American material contains both N. spathiger and N. 

 filicoUis, with two additional forms not found elsewhere. 



For the study of the spicules the material was cleared in phenol 

 alcohol, while for the study of other characters specimens were either 

 cleared in glycerol or stained and mounted in balsam. Sections were 

 used to clear up certain points and to check up others. The spicules 

 of nearly 800 specimens were measured. Measurements were made of 

 the length and breadth of 350 eggs. 



Genus NEMATODIRUS Ransom, 1907. 



1907. Nematodirus Ransom, 1907fc, p. 4. 

 Generic diagnosis. — Metastrongylinae : Filiform, with reproduc- 

 tive organs in posterior body region. Anterior part of female and 

 entire length of male marked with longitudinal cuticular ridges de- 

 pending in number on the diameter of the specimen — usually 18 to 

 24. Cuticula inflated in head and neck region, and in the female 

 sometimes also between anus and posterior end. Coarse, transverse 

 striations within the inflated area, but not elsewhere. Mouth open- 

 ing oval and surrounded by six inconspicuous papillae, the two 

 lateral papillae being largest. Buccal cavity very short. Esophagus 

 400 to 700 jx long, evertable in the anterior region, and armed with a 



