198 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. So. 





Female 70 mm. long with a maximum thickness of 336 [x. The buc- 

 cal cavity is 50 \i long ( ? ) . The muscular esophagus is 8T0 ^ long ; 

 the total length of the esophagus is one-ninth of the body length. 

 The tail is very short and conical, with the orifices of the caudal glands 

 near its extremity. The ^ulva is in the posterior portion of the body, 

 about 8 mm. anterior of the anus. The ovijector 

 is characterized by a vestibule and a sphincter 

 forming a cylindrical tube 1 mm. long and lined 

 with a thick cuticle (fig. 256). This is followed 

 by a musculo-epithelial tube 16.3 mm. long, which 

 / H /| extends anteriorly and divides into two divergent 



T branches. The eggs have a thick shell, 42 jx long 

 by 25 fi wide, and contain an embryo when ovi- 

 posited. 



Host. — Dipodlllus canipestris {Dipod'dla ccmi- 

 pestris). 



Location. — Cardiac region of the stomach, in 

 the mucosa. 



Localitij. — Pjou Saada, Algeria. 

 The principal, and almost the only feature, 

 which distinguishes this species from Gongy- 

 Jonema neoplastlcum is the presence of addi- 

 tional caudal papillae in the male. The posterior 

 extremity of G. neoplasticu7n is figured with tlie 

 bend to the left, which also occurs in G. hrevlsplc- 

 ulum. It appears quite possible that Fibiger and 

 Ditlevsen (1914), in their excellent study of G. 

 neoplastlcum,^ may have overlooked some papillae, 

 and that a restudy will show that G. hrevispicu- 

 lum must be regarded as a synonym of G. neo- 

 plastlcum. Until this point has been determined 

 it will be safer to retain the two species, keeping 

 in mind the possibility that they are identical. 

 The fact that G. neoplastlcum has been devel- 

 oped in such hosts as the rat, rabbit, and guinea 

 one of which is a notorious wanderer and cosmopolite, speaks 



Fig. 250.— Gongylo- 

 nema brevispicu- 

 LUM. Vagina and 

 OVIJECTOR. I, Union 

 OF two portions of 

 ovijector. After 

 Seurat, 1914. 



for their identity in connection with their other features in common. 



GONGYLONEMA (?) species Hall, 1916. 



Specific diagnosis. — Gongylonema .(?) (p. 101): Very fine fila- 

 mentous worms, 8.1 cm. long. 



Host. — Castor flher. 



Location. — Stomach. 



L.ocality. — United States (Michigan?). 



Morgan (1868), in his work on the American beaver, states in a 

 footnote on page 73: "In the stomach of the beaver I have found 



