THE ROUNDWORMS OF DOMESTIC SWINE. 33 



2. Stiles and Hassall (1894e) include Spiroptera strongylina in their 

 preliminary catalogue of the parasites in the collection of the United 

 States Bureau of Animal Industry. They report the parasite as com- 

 mon. The specimens referred to by them (No. 2057 of the bureau 

 collection) have been reexamined by the writer, and many specimens 

 of Physocephalus sexalatus were found with the specimens of Arduenna 

 strongylina. Stiles and Hassall's specimens were collected at Ben- 

 ning, D. C. 



3. Francis (1894a) reported Spiroptera strongylina in a list of para- 

 sites collected by him in Brazos County, Tex. It is reported as com- 

 mon. The specific name is followed by an interrogation point in 

 parenthesis to indicate the author's doubt as to the correctness of the 

 identification. Considering the inaccuracy of the descriptions of 

 Arduenna strongylina, then available, it is not to be wondered that 

 Francis, noticing the discrepancies between the descriptions and the 

 anatomical features seen in his specimens, should question the identi- 

 fication. On the other hand, it is quite possible that the specimens 

 collected by Francis were Physocephalus sexalatus, or included this 

 species. 



4. Kaupp (1910) reported the occurrence of Spiroptera strongylina 

 in hogs raised in the Missouri Valley. His article is illustrated with 

 original drawings, one of which shows the caudal end of the female 

 with the vulva apparently on the right side, a little anterior of the 

 anus. 



For the sake of additional data, letters were sent to the inspectors 

 in charge at some of the principal slaughterhouses of the United 

 States, requesting information in regard to the occurrence of Spirop- 

 tera strongylina in hogs. Replies were received from South Omaha, 

 Chicago, St. Louis, and Kansas City. The inspector in charge at 

 South Omaha reported that fully 80 per cent of the hogs examined 

 were infested. It was reported from St. Louis that "the worms 

 occur in considerable numbers in the mucous coating of the stomach." 

 The parasite is reported as very frequent in hogs slaughtered at 

 Kansas City; out of 1,450 hogs examined, 1,052 were infested. In 

 some stomachs as many as 140 worms were collected. From Chicago 

 it was reported that 1,000 hogs had recently been examined, and 690 

 were found infested. The worms were found on the surface of the 

 mucous membrane or attached by the head. Several hundred 

 specimens obtained by scraping the mucosa from the stomachs of a 

 number of infested hogs were received from this city. These worms 

 were found to be Arduenna strongylina and Physocephalus sexalatus. 



Reports from slaughterhouses regarding the occurrence* of parasites 

 are of but little value in determining the localities infested by a given 

 parasite, as the animals slaughtered are received from widely scat- 

 tered sections of the country. Enough data have been gathered, 



