PLATE XIII. 



EXPLANATION. 

 Fig. 



1-9. MONAS Dallingeri, S. K. (after Dallinger and Drysdale), vol. i. p. 233.— i, 

 Normal adult form, x 2000 ; 2, monad preparing to assume an encysted 

 state; 3, 4, 5, progressive phases following upon encystment, and resulting 

 m the production of a spherular aggregation of elongate vermicular macro- 

 spores ; 6, the same macrospores liberated as simple monads resembling the 

 parent, but of smaller size ; 7, conjug.ation of larger and smaller monads ; 

 8, encystment resulting from such conjugation ; 9, the compound cyst 

 bursting and liberating infinitesimally minute microspores. 

 10-18. MoNAS FLUIDA, Duj., vol. i. p. 234.— 10, Typical adult monad, x 1000 ; 11-16, 

 nietamorphic forms of similar adult monads ; 17, conjugation of two zooids ; 

 1 8, their encystment. 



19. MoNAS IRREGULARIS, Pty. (Cienkowski), vol. i. p. 236, x 350. 

 20, 21. MONAS OBESA, Stein sp., vol. i. p. 236, x 650 (Stein). 

 22-24. MoNAS RAMULOSA, Stein sp., vol. i. p. 235, X 600 (Stein). 

 25-26. Leptomonas Buetschlii, S. K. (Butsch.), vol. i. p. 243.-25, A group attached 



by their posterior extremities, x 600 ; 26, a free-swimming monad, x 1 500. 

 27, 28. Ophidomonas jenensis, Ehr., vol. i. p. 244, x 600 (Ehr.). 



29-34. Herpetomonas MUSC^-DOMESTlCiE, Burnet sp. (Stein), vol. i. p. 245.-29-32, 

 Polymorphic phases of the adult monads, x 650 ; 33 and 34, monads dividing 

 by longitudinal fission. 



35-40. Herpetomonas Lewisii, S. K. (Lewis), vol. i. p. 245.-35-38, Various contours 

 of the adult organism, x 800 ; 39, two red and forty-one colourless corpuscles 

 of the rat's blood which they inhabited, equally magnified to show pro- 

 portionate size. 



41, 42. SCYTOMONAS PUSILLA, St., vol. i. p. 241, X 650 (Stein). 



43, 44. Pleuromonas jaculans, Pty., vol. i. p. 249, X 500 (Perty). 



45. Merotricha bacillata, Meresch., vol. i. p. 249 (Dimensions unrecorded) 

 (Mereschkowski). 



46, 47. Cyathomoxas elongata. From., vol. i. p. 243.-47, Dividing by longitudinal 

 fission, X 600 (De Fromentel). 



48. Cyathomonas TURBINATA, From., vol. i. p. 242, x 400 (Dc Fromentel). 



