PLA TE XIII. 



EXPLANATION. 



Fig. 



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

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

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

 in the production of a spherular aggregation of elongate vennicular macro- 

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

 parent, but of smaller size ; 7, conjugation 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. 1. p. 234. — lo. Typical adult monad, x 1000 ; 11-16, 

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

 18, their encystment. 



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



20, 21. MoNAS OBESA, Stcin 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. (Biitsch.), 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^E-DOMESTiCiE, 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) 

 (M ereschkowski) . 



46, 47. Cyathomonas 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 (De Fromentel). 



