NO. 2131. NEAIATODJJ PARASITES OF ROUENTS—HALL. 83 



general appearance. They are, however, readily distinguished, and 

 the presence of the two species has been recognized for almost a 

 century. Since Rudolphi has confused two species under a single 

 name it is necessary to restrict the name used by him to one of these 

 species. I have accordingly left as Oxyuris ohi'>elata the form which 

 is evidently not covered by Oxyuris tetraptera. 



The maximum length, 5.7 mm., given for the female by Dujardin 

 (1845) is in excess of that I have found, which fact is possibly asso- 

 ciated wdth the measurements of the distance from the head to the 

 vulva, 1 to 1.33 mm. Von Linstow (1879«) states that back of the 

 vulva aperture is a chitinized hollow cylinder with a somewhat wider 

 aperture which seems to serve for the reception of the male accessory 

 piece. I have not been able to identify this structure. Males are 

 apparently very rare in this species, contrary to my experience with 

 O. tetraptera^ and none is available to me. I have had to depend 

 on other writers for a description of the male. Von Linstow (1884) 

 notes that males are very rare and apparently short lived in this 

 species. He adds that females 3G0 /u. long have the vulva closed with 

 a brown plug, the sign of fertilization already accomplished. Von 

 Linstow also notes a fungus growth as common on the skin of many 

 females. This fungus starts at the anus (fig. 96) and apparently 

 arises from fungi growing in the excrement. From this point, where 

 it shows as a sepia-brown body visible to the naked eye, it spreads 

 posteriorly to the end of the tail and anteriorly to the head. Neo- 

 toTTui mexlcana faJlax is recorded here as a host for the first time, the 

 host being collected in Colorado. 



Seurat (1916: See Addendum, p. 224) makes this type of the new 

 genus Syphacia. He regards O. stro7via as a synonym. 



OXYURIS PUGIO Hemprich and Ehrenberg, 1828. 



Specific diagnosis. — Oxyuris (p. 65) : Head alate. Mouth bare. 



Male unknovv^n. 



Female " Trilinearis " (three lined or three lines (6.5 mm.) long?). 

 Anterior portion of body ovigerous. Tail semialate. 



Host. — Procavia syriaca {Hyrax syriacus). 



Location. — Large intestine. 



Locality. — Palestine. 



This form has never been described properly. Nassonov (1897) 

 states that he found this form, but, contrary to what some of his 

 reviewers state, he published no study of it, merely quoting Hemp- 

 rich and Ehrenberg. 



