412 PARASITES OP ANIMALS 



out significance, but as yet we are entirely unacquainted with the 

 larvaD of Stephanurus. If no intermediary bearers are necessary 

 to its development, we ought not to have to wait long for a 

 complete record of the life- history of Stephanurus dentatus. In 

 conclusion, I will only further remark that since thousands of 

 hogs are infested by this entozoon the subject is worth further 

 investigation. I believe that Prof. Fletcher brought the matter 

 under the notice of the United States National Swine Breeder's 

 Association, which met at Indianapolis in November, 1872, but 

 with what success I have been unable to learn. The wealthy 

 agricultural societies of Great Britain pay little or no regard to 

 the subject of parasites, although thousands of valuable animals 

 annually perish from the injurious action of entozoa. 



Of the remaining nematodes infesting swine I must particu- 

 larly mention Sclerostoma (Strongylus) dentatum and Strong i/lnx 

 paradoxus, the last named being generally regarded as identical 

 with Dujardin's S. elongatus. The first of these two parasites 

 infests the small intestines, the male and female worms alike 

 measuring about '' i n length. The females are sometimes a 

 trifle longer. The Sclerostoma dentatum is an abundant para- 

 site, infesting all varieties of swine and also peccaries ; but it 

 is apparently incapable of serious injury to the bearer. 

 Schneider selected the male S. dentatum for classificatory 

 purposes. In this worm the arrangement of the rays of the 

 hood is simple, forming a good central type. Dr D. V. Dean, 

 in his excellent report of St Louis Board of Health (1874), 

 speaks of Strongylus dentatus as if it were the same entozoon 

 as Stephanurus. The confusion of nomenclature would have 

 been avoided if Diesing had called the renal worm Stephanurus 

 Nattereri. I hope this title will yet be adopted to prevent 

 future mistakes. The lung-worm (S. paradoxus) is by no 

 means harmless, being a frequent cause of fatal husk in young 

 pigs. It is a viviparous worm, the females acquiring a length 

 of 1^", whilst the males rarely exceed f". Under the title 

 Gongylonema pulchwnn, Molin has noticed yet another filari- 

 form nematode infesting the wild hog ; and, lastly, the lamented 

 Eussian traveller, Fedschenko, has published a full description 

 of a new species of Gnathostoma (G. hispidum), which infests 

 the coats of the stomach alike of the wild and domestic hog. 

 One of the most interesting parasites of swine is the large 

 acanthocephalous entozoon (Echinjorhynchus gigas). It infests 

 the small intestines both of the wild and domesticated hog, and 



