NO. 2131. 



NEMATODE PARASITES OF RODENTS— HALL. 



85 



m 



men, but is usually about 1 mm. or less. The club-shaped esophagus 

 terminates in the esophageal bulb. The intestine is considerably 

 dilated anteriorly, is sharply constricted behind the en- 

 larged portion, and then pursues an almost rectilinear 

 course with fairly constant diameter to the anal 

 aperture. 



Male 5 to 8 mm. long and 370 to 580 [jl thick. The 

 posterior extremity of the body (fig. 97) is spirally en- 

 rolled and bears a short conical projection at the tip. 

 The spicule is about 250 [x long and is 16 jjl thick at the 

 base. It is directed posteriorly toward the projection 

 on the tip of the tail. The cloacal aperture is about 130 

 [J, from the posterior extremity of the body. 



Female 12 mm. long and with a maximum thickness 

 of about 1 mm. The esophagus is from 500 to 700 ^ 

 long. The bulb has a diameter of 200 (x. The anus is 

 2 to 2.5 mm. from the posterior extremity of the body. 

 The vulva (fig. 98) is about 1.7 mm. from the anterior 

 extremity of the body. The uterus shows large dilata- 

 tions full of innumerable eggs. The eggs (fig. 99) are 

 of the typical asymmetrical shape. They are 70 to 75 [a 

 long and 35 to 38 [x thick. The embryonic mass occupies 

 only the central portion, leaving a considerable clear 

 portion. 

 Host. — Hystrix crUtata. 



Location. — Intestine. 

 Locality . — Massaua , Eritrea, 

 Italy. 



I have taken the dimensions of the 

 esophagus, given by Setti in his gen- 

 eral discussion, as probably apply- 

 ing to the female. Also I have dis- 

 regarded his statement that the egg 

 shape is either asymmetrical or 

 symmetrical. This depends entirely 

 on the point of view. The Oxyurls 

 egg is flattened on one side, and this is what is meant by asymmetrical 

 here. 



OXYURIS STROMA von Linstow, 1884. 



:ri 



:'a 



Fig. 97. — OxYURis 



STOSSICHl. POSTE- 

 ElOK EXTEEMITY OF 

 MALE. X 50. AfTEE 



Setti, 1897. 



Fig. 98. — Oxt- 



URIS STOSSICHl. 



Female. X 10. 

 After Setti, 

 1897. 



Specific diagnosis. — Oxyuris (p. 65) : Three 

 hyaline lips (fig. 100) about a triangular aperture 

 which is first surrounded by a circular disk. Dor- 

 sally and ventrally the underlying parenchyma pro- 

 jects to form three elevations on each side. In each case the median 



Fig. 99.— Oxyuris 

 STOSSICHl. Eggs. 

 X 100. After 

 Setti, 1897. 



