EXPLANATION OF PLATE XV. 



Fig. 



1-17. Heteromita lens, Miill. sp., vol. i. p. 291. — I and 2, normal adult monad in the 

 fixed and free-swimming conditions, x 800 ; 3 and 4, irregular-shaped amoebi- 

 form conditions ; 5 and 6, two monads attached close to each other and 

 about to coalesce ; 7, coalescence or conjugation ; 8 and 9, phases succeed- 

 ing conjugation, productive in the last instance of a spheroidal sporocyst ; 

 10, sporocyst, with contents consisting of innumerable microspores ; 11-14, 

 minute, uniilagellate, monadiform germs, developed from such microspores, 

 and either single or adherent in diverse combinations, x 2500 ; 15, two 

 sporocysts, containing eight or sixteen macrospores ; 1 5, a sporocyst with four 

 macrospores only ; 17, the same sporocyst burst open and giving birth to four 

 biflagellate germs differing only in size from the parent animalcule, x 1000. 



18-28. Heteromita rostrata, S. K. (Dallinger and Drysdale), vol. i. p. 293. — 18, 

 attached condition of adult monad, the outhnes at a and b indicating the 

 positions to which the body is projected by the uncoiling and extension of the 

 posterior and adherent flagellum, x 1500; 19 and 20, successive phases of 

 longitudinal fission ; 21 and 22, conjugation of two monads ; 23, triangular 

 sporocyst resulting from such conjugation ; 24, the same sporocyst bursting 

 at its angles and releasing the enclosed microspores, x 2000 ; 25 and 26, 

 development at phases of the released microspores, liberated from the trian- 

 gular sporocyst, x 2500 ; 27 and 28, further progressive stages towards the 

 attainment of the parent form at the end of eight and ten hours, x 2500. 



29-41. Heteromita uncinata, S. K. (Dall. and Drysd.), vol. i. p. 294. — Normal adult 

 monad, X 1500 ; 30, irregular semi-amceboid phase, preceding fission ; 31, 

 fission ; 32, conjugation of two monads of diverse size ; 33, conjugation of 

 four monads ; 34-39, sporocyst resulting from conjugation with successive 

 phases of segmentation of its contents, producing finally a mass of minute 

 microspores ; 40, bursting of sporocyst and release of contents as minute 

 uniflagellate germs; 41, one such germ a few hours later, having nearly 

 attained the parent form. 



42, 43. PSEUDOSPORA VOLVOCIS, Cienk., vol. i. p. 304, X 400.— Natatory and repent 

 conditions of the same zooid (Cienkowski). 

 44. Heteromita adunca, Meresch., vol. i. p. 297, x 1500 (Meresch.). 



45, 46. COLPONEMA loxodes, St., vol. i. p. 297.-45, dorsal, and 46, ventral aspect, x 

 600 (Stein). 



47, 48. Phyllomitus undulans, St., vol. i. p. 299, X 600 (Stein). 



49-60. Spiromonas angustata, Duj. sp.,vol. i. p. 298. — 49-52, Free-swimming monads, 

 with their bodies in all cases, excepting 52, variously contorted, x 1500; 53, 

 an adherent monad ; 54, amoebiform condition ; 55, two amoebiform monads 

 conjugating ; 56-59, successive phases of encystment and spore-production ; 

 60, free-swimming monad, as represented by Dujardin. 



61-64. Heteromita globosa, St. sp. (Stein), vol. i. p. 295.— 61-63, Normal adult 

 monads, x 600 ; 64, a number of monads tenanting the cell of an OLdogo- 

 nium, and feeding on its contents. 



65, 66. Heteromita ovata, Duj., vol. i. p. 295. — Dorsal and lateral aspects, x 600 

 (Stein). 



67-78. POLYTOMA uvella, Miill. sp., vol. i. p. 302. — 67-69, Animalcules showing loop- 

 like flexure of the basal region of the flagella, the example in the first instance 

 being attached by this loop-like coil, as observed by the author, x 800 ; 70 and 

 71, examples with supposed basal inflations of the flagella, or independent 

 knobbed appendages, as represented by Messrs. Dallinger and Drysdale ; 

 72-74, successive phases of multiplication by complete segmentation of 

 the internal contents (Dallinger and Drysdale) ; 75, multiplication by the 

 breaking up of the endoplasm of the posterior region only into minute 

 angular germs (D. and D.) ; 76, the same angular germs, more highly magni- 

 fied (D . and D.) ; "Ji^ conjugation of two animalcules (D. and D.) ; 78, rupture 

 of sporocyst resulting from such conjugation, and release of microspores, 

 X 800 (D. and D.). 



