ART. 4 NEW NEMATODE WORMS FROM RODENTS PRICE 6 



Ions in the male. It differs, however, in that the former species is 

 about twice the size of the latter, the tail of both sexes is proportion- 

 ally longer and more slender, the spicule and gubernaculum larger, 

 and the egg smaller. The presence of a spiny process caudad of the 

 cloacal aperture also appears to be characteristic of the new species. 

 This species is readily distinguishable from S. pallaryi (Seurat, 1915) 

 by the number of ventral mamelons, there being but two in the latter 

 species. 



Yorke and Maplestone (1926) list S. honnei Thiel, 1925, from 

 Mycetes seniculus, and S. siossickl (Setti, 1897) from Hystrix cris- 

 tata, in addition to S. obvelata and &. paUaryl^ as belonging to the 

 genus Syphacia. Travassos (1926), however, has shown that S. 

 honnei is identical with Enterohius minutus (Schneider, 1866). The 

 inclusion of S. stossicM { = Oxyuris stossicJii) in this genus by Tra- 

 vassos (1923) appears to the writer to be subject to question. The 

 bosses or mamelons figured by Setti (1897) are too small and sit- 

 uated too near the cloacal aperture to be considered comparable to 

 the large mamelons of the other species of the genus ; there also ap- 

 pears to be an absence of caudal alae, papillae, and a gubernaculum. 

 On the basis of these differences it is the opinion of the writer that 

 if S. stossichi is restudied, it will probably be found to represent a 

 new genus. 



HELIGMOSTRONGYLUS HASSALLI. new species 



Specific diagnosis. — Heligmosii'ongyJus : Small slender worms, 

 reddish in color and loosely coiled when fresh, yellowish and almost 

 straight when preserved in alcohol. Cuticle of the anterior end 

 dilated and coarsely striated transversely. (Fig. 6.) The cuticle of 

 Ihe body is finely striated transversely and is also provided with 

 small striated bosses (fig. 7) arranged in the form of 14 to 16 longi- 

 tudinal lines. These lines extend from the cephalic dilation to the 

 vulva of the female, and to the bursa of the male. A well-defined ala 

 extends along the left side of the body from the cephalic dilation to 

 the vulva in the female, and to near the bursa in the male. Cervical 

 papillae not observed. The mouth opening is triangular and bears 

 2 submedian papillae, and one amphid (the lateral papilla of various 

 authors) on each side. (Fig. 8.) 



Male 5.3 to 6.8 mm. long by a maximum width of 122/x at the 

 middle of the body. Tlie cephalic expansion is 38/x wide and 75ju. 

 long. The esophagus is simple, 290 to 300/x long by 15/x wide at the 

 anterior end and increasing to 40,w in width at the posterior end. 

 The nerve ring surrounds the esophagus about 150/i from the an- 

 terior end. The excretory pore is situated immediately caudad 

 of the posterior end of the esophagus. The bursa consists of two large 



