EXPLANATION OF PLATE I. 



Fig. 



r, 2. Trypanosoma sanguinis, Grube, vol. i. p. 219, x 600 (Ray Lankester). 



3-6. Trypanosoma Eberthi, S. K., vol. i. p. 219, x 1200 (Eberth). 



7, 8. ACTINOMONAS PUSILLA, S. K., vol. i. p. 227. — 7, Zooid attached by a single stalk- 

 like filament ; i, zooid attached by a number of its ray-like pseudopodia, 

 X 800. 

 9-11. ACTINOPHRYS SOL, Ehr., vol. i. p. 225. — Successive developmental phases out of 



a primary monadiform germ, as observed by the author, x 600. 

 12-17. MagospHjERA planula, Hkl., vol. i. p. 323. — 12, Adult spheroidal colony-stock, 

 X 240; 13, ideal optical section of the same ; 14, a single isolated zooid 

 derived from the disintegration of the social colony-stock; 15, a similar 

 zooid having assumed an amoeboid phase ; 16 and 17, encysted zooids, the 

 one at 17 having divided by segmentation into four spheroidal sporular 

 bodies (Haeckel), 



18. ACTINOMONAS MIRABILIS, S. K., vol. i. p. 227, X 8oo. 



19, 20. Mastigamceba ramulosa, S. K., vol. i. p. 222. — Extended and contracted con- 

 ditions, X 400. 

 21, Mastigamceba aspera, Sclz., vol. i. p. 221, x 170 (Schulze). 

 22, 23. Mastigamceba monociliata. Carter sp., vol. i. p. 222, dimensions unrecorded 

 (Carter). 



24, EUCHITONIA Virchowii, Hkl., vol. i. p. 228, X 370 (Haeckel). 



25. Spongocyclia charybdea, Hkl., vol. i. p. 229, X 72 (Haeckel). 



26, 27. Rhizomonas verrucosa, S. K., vol. i. p. 224. — 26, Animalcule enclosed within 

 granular gelatinous sheath, x 750 ; 27, example devoid of such covering. 



28, 29. PODOSTOMA FILIGERUM, C. & L., vol. i. p. 225. — 28, Animalcule with flagelliferous 

 pseudopodia extended ; 29, example with appendages entirely retracted, 

 X 250 (Clap, and Lach.). 

 30. Mastigamceba simplex, S. K., vol. i. p. 221. — Having attached by a posteriorly 

 extended thread of sarcode the frustule of a diatom, probably ejected from 

 its body, x 800. 



31-33. Reptomonas caudata, S. K., vol. i. p. 223. — 31, Normal animalcule, profile view, 

 X 800 ; 32, Dorsal view of example with short posterior pseudopodal exten- 

 sions ; 33, a similar example in the act of ingesting food by the peripheral 

 extension of its body-sarcode. 



34-44. NOCTILUCA MILIARIS, Suriray, vol. i. p. 397. — 34, Normal adult animalcule, X 40 ; 

 35 and 36, peripheral regions of two animalcules having variously developed 

 masses of germinal bodies, x 50 (Cienkowski) ; 37, a similar germinal patch 

 more highly magnified, and showing its composition of uniflagellate monadi- 

 form elements (Cienk.) ; 38-40, isolated monadiform germs in different 

 aspects and phases of development, x 500 (Cienk.) ; 41, more abnormal 

 zoospore-Hke germ, x 500 (Cienk.) ; 42, entire adult animalcule, dorsal view, 

 showing median groove, stylate rod, and tooth-like process (Huxley) ; 43, 

 latero-inferior view, showing oral cavity with tooth-like process and contained 

 cilium (Huxley) ; 44, conjugation of two animalcules (Cienk.). 

 45. Vol. i. p. 399. Encysted condition oi Nociiluca, figured by Wyville Thomson as 

 a new diatom, Pyrocystis pseudo-noctiliica, x 30 (Wyv. Thom.). 



46-53. Leptodiscus medusoides, Hwg. (Hertwig), vol. i. p. 400.— 46 and 47, Two 

 animalcules with edges variously folded, nat. size ; 48, animalcule extended, 

 X 40 ; 49, zooid in vertical section, showing the thicker central and more 

 attenuate peripheral regions ; 50, segment of a similar section more highly 

 piagnified, showing oblique tubular oral fossa, superiorly attached flagellum, 

 and at a a a superficial oil-like globules ; 51, endoplast or nucleus of adult 

 animalcule, x 100 ; 52 and 53, supposed developmental phases of Lepto- 

 discus, with, in the former instance, one half of the cyst-like body-wall 

 contracted. 

 54. Pyrocvstis rusiFORMis, Wyv. Thomson, vol. i. p. 399. — Probably the encysted 

 condition o{ Leptodiscus, x 35 (Wyv. Thorn.). 



