NO. 2131. 



NEilATODE' PARASITES OF RODENTS— HALL. 



155 



Male 2.6 to 2.8 mm. long and 90 to 100 /x thick. The Large bursa 

 is trilobed, and the posterior lobe is very small. The ventro- ventral 

 and latero-ventral rays are divergent, and the medio-lateral and 

 externo-lateral rays are divergent. The dorsal ray terminates in 

 four digitations. The spicules are long 

 and filiform, with a sinuous distal ex- 

 tremity. 



Female 3.5 mm. long and 130 fi thick. 

 The posterior extremity is truncate. The 

 anus is about 71 /a from the tip of the tail. 

 The vulva is about 110 fi from the tip of 

 the tail. The single uterus contains nu- 

 merous ellipsoidal eggs. The eggs are G3 

 by 28 [M in diameter. 



Host. — Ephnys nor cegicus [Mas decu- 

 manus). 



Location. — Small intestine. 



Locality. — Rio de Janeiro, Manguinhos, 

 Brazil. 



Life history. — Unknown. 



The statements regarding the rays as 

 given above are to be regarded as the 

 present writer's interpretation of Tra- 

 vassos's statements. It is greatly to be de- 

 sired that every ray in the strongyle bursa 

 be referred to specifically in descriptions 

 rather than that some of them be considered as individual rays which 

 branch. The dorsal ray may be treated as an exception to this, but 

 it is very confusing to treat the ventral rays and combinations of the 

 lateral rays as one ray. 



Fig. 200.— Heligmosomum vexh.- 

 LATUM. Anterior extremity 



OF FEM^ULE. ENLARGED. 



HELIGMOSOMUM VEXILLATUM Hall, 1916, new species. 



ft 



Specif c diagnosis. — Heligmosomum (p. 149) : Lips indistinct. 

 Cuticle of head very slightly dilated. Cuticle with very fine and 

 close, but very distinct transverse striation. A number of wavy 

 cuticular markings, possibly 8 or 10 in number, formed by a sort 

 of permanent cuticular folding, originate at the head and continue 

 for some distance back (fig. 200), the distance in some females being 

 as much as 500 ix. Two of these pennantlike markings, from which 

 the species takes its name, seem to be constant and more prominent 

 than the others. The other markings are not always evident. In- 

 testinal cells contain small amounts of refractive granules distributed 

 throughout the entire length of the intestine. 



