PLATE 21. Entozoa. 



Figure 



1. Echinococcus veterinorum (hominis) ; 1 a, in the contracted state ; 1 b, hooks ; 



1 c, d, f, in the expanded state ; 1 e, imperfectly developed individual. 



2. Echinococcus veterinorum (liominis), cyst reproducing by external gemmation. 



3. Cysticercus cellulosce, a, nat. size ; 3 b, C. fasciolaris, head of. 



4. Anguillula fluvia tilis. 



5. Anguillula aceti. 



6. Anguillula tritici. a, b, ova ; c, mature individual ; <#, imperfectly developed 



individual. 



6 e. Dochmius (Anchylostomum) duodenalis, male; #, head of female; + , male, 

 t, female, nat. size. 



7. Gyrodactylus auriculatus, 8 diameters. 



8. Ascaris vermicularis ; 8 a, head; d, stomach; 0, oesophagus; g, anus; h, ovaries ; 



k, oviduct. 



9. Ascaris lunibricoides ; , front view of head; 96, tail of male, with spicula ; 



9 c, side view of head. 

 10. Ccenurus cerebralis, portion of a cyst, 



12. Tcenia solium, head of, side view ; two of the suckers only are visible. 



13. Tcenia solium, head of, front view ; all the four suckers are visible. 



14. Tcenia solium, a single joint, injected, a, gastric (?) canals ; 6, vascular canals ; 



c, testicular capsule ; d, spermatic duct ; e, oviduct ; the dark ramified organ 

 is the ovary. 



15. Tcenia solium, ovum of. 



16. Trichina spiralis, lying within its cyst, imbedded in muscle. 



17. Trichina spiralis, removed from its cyst. 



18. Trichina spiralis, internal organs. 



19. Trichocephalus dispar, male. 



20. Trichocephalus dispar, portion of the neck. 



21. Trichocepl talus dispar, female ; 21 a, ovum. 



22. Monostoma verrucosum, ovum of. 



23. Tcenia variabilis, ovum of. 



25. Gregarina sipunculi. 



26. Gregarina sipunculi, with two enclosed cells. 



27. Caudate pseudo-navicula, from the abdominal cavity of Sipunculus nudus. 



28. Gregarina Sieboldii. 



29. Young pseudo-navicula cyst of Gregarina scenuridis, from testis of Scenuris 



variegata, consisting of loosely connected ovate cells, without an outer 

 envelope. 



30. The same, with an outer envelope. 



31. More advanced pseudo-navicula cyst of the same Gregarina, with two cells 



containing rounded pseudo-naviculse. 



32. The same, with elongated pseudo-naviculse ; the cyst has three cell-like bodies 



on its surface. 



33. The same with a single cavity, containing elongated pseudo-naviculaB. 



34. Two Gregarince s&nuridis, adherent by their ends. 



35. EchinorTiynchus anthuris, head, 25 diameters. 



