PLATE 21.— Entozoa. 



Figure 



1. EcMnococcus 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. EcMnococcus veterinorum (Jiominis), cyst reproducing by external gemmation. 



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



4. Anguillula fluvia tills. 



5. Anguillula aceti. 



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



individual. 



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

 f, female, nat. size. 



7. Gyrodactylus auricidatus, 8 diameters. 



8. Ascaris vermicidaris ; 8 a, head ; d, stomach; e, oesophagus; g, anus; h, ovaries ; 



Tc, oviduct. 



9. Ascaris lumbricoides; a, front view of head ; 9 6, tail of male, with spicula ; 



9 c, side view of head. 

 10. Ccenurus cerebralis, portion of a cyst, 



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



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



14. Taenia solium, a single joint, injected, a, gastric (?) canals ; b, vascular canals ; 



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

 is the ovary. 



15. Taenia solium, ovum of. 



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



17. Trichina spiralis, removed from its cyst. 



18. TricJiina spiralis, internal organs. 



19. Trichocephalus dispar, male. 



20. Tricliocepludus dispar, portion of the neck. 



21. Tricliocepludus dispar, female ; 21 a, ovum. 



22. Monostoma verrucosum, ovum of. 



23. Teenia variabilis, ovum of. 



25. Gregarina sipunculi. 



26. Gregarina sipunculi, with two enclosed cells. 



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



28. Gregarina, Sieboldii. 



29. Young pseudo-navicula cyst of Gregarina samuridis, 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-navicula?. 



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



on its surface. 



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



34. Two Gregarincv srenuridis, adherent by their ends. 



35. Ecliinorhynchus anthuris, head, 25 diameters. 



