394 ENTOZOA. 



comprising only two separate species, wliicli possess, however, 

 very considerable interest alike for tlie naturalist and the 

 pathologist. 



1. PeNTASTOMA TiENIOIDES. 



p. tmnioides, Rudolphi ; Bremser ; Diesing ; etc. 



P. denticulatum, Rudolphi ; Bremser ; etc. 



P. serratum, Rudolphi ; Diesing ; Miram ; Dujardin. 



P. emarginatum, Rudolphi, 



P. settenii, Diesing. 



P. zera, Crephn. 



Linguatula toenioides, Lamarck ; Cuvier ; Owen ; etc. 



L. lanceolata, Blainville. 



L. denticulata, Lamarck. 



L. serrata, Froelich. 



L. ferox, Kiichenmeister. 



Poly stoma tcenioides, Rudolphi. 



P. denticulatum, Rudolphi. 



P. serrata, Zeder ; Rudolphi. 



Tetragulus cavioB, Bosc ; Kaufman. 



Prionoderma lanceolata, Cuvier. 



EcJiinorhynchus caprce, Braun. 



Tcenia lanceolata, Ohaubert. 



T. rhinaria, Pilger ; Greve. 



T. cajprina, Abildgaard ; Grmelin. 



Halysis caprina, Zeder. 



Monostoma settenii, Numan ; Siebold. 



General and Specific Characters. — An entozoon belonging to tlie family of Acarid^, 

 and having no structural connection with the true helminths ; in the adult state charac- 

 terized by the possession of a vermiform, lancet-shaped body, flattened at the ventral 

 surface, attenuated posteriorly, and marked transversely by about ninety rings ; cephalo- 

 thoracic segments continuous with the body, supporting each a pair of strong retractile 

 chitinous claws, these four feet or limbs being biserially disposed on either side of the 

 middle line ; head somewhat truncated or abruptly rounded, mouth broadly oval and 

 armed with a homy lip ; integuments perforated with numerous so-called respiratory 

 openings or stigmata, which are, however, wanting in the cephalic segment: general 



