EXPLANATION OF PLATE XV. 



FIG. 



1-17. HETEROMITA LENS, Mull. sp. i and 2, normal adult monad in the fixed and free- 

 swimming conditions, x 800 ; 3 and 4, irregular-shaped amoebiform conditions ; 

 5 and 6, two monads attached close to each other and about to coalesce ; 

 7, coalescence or conjugation ; 8 and 9, phases succeeding conjugation, pro- 

 ductive in the last instance of a spheroidal sporocyst ; 10, sporocyst, with 

 contents consisting of innumerable microspores ; 11-14, minute, uniflagellate, 

 monadiform germs, developed from such microspores, and either single or 

 adherent in diverse combinations, x 2500; 15, two sporocysts, containing 

 eight or sixteen macrospores ; 15, 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). 18, attached condition 

 of adult monad, the outlines 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 triangular 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.). Normal adult monad, 

 x 1500 ; 30, irregular semi-amoeboid 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 segmen- 

 tation 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., X 400. Natatory and repent conditions of 



the same zooid (Cienkowski). 

 44. HETEROMITA ADUNCA, Meresch., x 1500 (Meresch). 



45, 46. COLPONEMA LOXODES, St. 45, dorsal, and 46, ventral aspect, x 600 (Stein). 



47, 48. PHYLLOMITUS UNDULANS, St., x 600 (Stein). 



49-60. SPIROMONAS ANGUSTATA, Duj. sp. 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 GLOBOSUS, St. sp. (Stein). 61-63, Normal adult monads, x 600 ; 

 64, a number of monads tenanting the cell of an QEdogonium, and feeding on 

 its contents. 



65, 66. HETEROMITA OVATA, Duj. Dorsal and lateral aspects, x 600 (Stein). 



67-78. POLYTOMA UVELLA, Mull. sp. 67-6.7, 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.) ; ;6, the same angular germs, more highly magni- 

 fied (D. and D.) ; 7 , conjugation of two animalcules (D. and D.) ; 78, rupture 

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

 x 800 (D. and D.). 



