EXPLANATION OF PLATE XXIX. 



Fig. 



1-2. BURSARIA TRUNCATELLA, Miiller, vol. ii. p. 576.— I, Adult animalcule, x 50; 

 2, supposed young condition, x 200 (Stein). 



3. Balantidium entozoon, Ehr. sp., vol. ii. p. 577, x 100 (Stein). 



4. Nyctotherus CORDIFORMIS, Stein, vol. ii. p. 580, x 150. — an, anal aperture 



(Stein). 



5. Nyctotherus velox, Leidy, vol. ii. p. 581, x 200 (Leidy). 



6-9. Metopus SIGMOIDES, Clap. & Lach., vol. ii. p. 581. — 6 and 8, Extended, 7 and 9, 

 spirally contorted animalcules, x 200 (Stein). 



10. Plagiotoma lumbrici, Duj., vol. ii. p. 583, X 200 (Stein). 



11. CONDYLOSTOMA STAGNALE, Wrz., vol. ii. p. 584, X 150. — u, Undulating mem- 



brane (Wrzesniowski). 



12. CONDYLOSTOMA PATENS, MiiU. sp., vol. ii. p. 584, X 1 50 (Stein). 



13, 14. Spirostomum ambiguum, Ehr., vol. ii. p. 586.— 13, An extended, 14, a spirally 

 contorted zooid, x 150 (Stein). 



15. Blepharisma undulans, Stein, vol. ii. p. 585, x 150.— 7^, Undulating 

 membrane (Stein). 



16, 17. Balantidium coli, Malmsten sp., vol. ii. p. 578, x 200. — At 17 an example 

 preparing to divide by transverse fission, and having already developed at 

 p 2 3. second peristome (Stein). 



18. Leucophrys patula, Ehr. sp., vol. ii. p. 587, x 150.—^//, pharyngeal passage 

 (Stein). 



19,20. Folliculina stylifera, Str. Wright sp., vol. ii. p. 600. — In each instance the 

 anterior region of the lorica is alone represented, the peristome lobes of the 

 contained animalcule in Fig. 19 being fully expanded, while in Fig. 20 they 

 are entirely withdrawn, leaving the stylate appendage only projecting beyond 

 the orifice of the lorica. Dimensions unrecorded (Strethill Wright). 



21-28. Folliculina ampulla, Miiller sp., vol. ii. p. 597. — 21 and 22, Entire animal- 

 cule and distal region of peristome of var. aculeata, Clap, and Lach. ; at 

 24 numerous examples crowded on a shell of Spirorbis nautiloides, x 20 ; 

 25-27, examples showing the diverse plans of ornamentation of the lorica ; 

 28, normal type in its fully extended state, X 200 (Stein). 



29-32. Folliculina producta, Str. Wright sp., vol. ii. p. 599. — 29, Adult animalcule 

 in its fully extended state, x 200; 30-32, embryonic condition (Strethill 

 Wright). 



33-35. Folliculina elegans, Clap. & Lach. sp., vol. ii. p. 598. — 33 and 34, Adult 

 animalcules, ventral and lateral aspects, x 200 (Stein) ; 35, empty lorica 

 showing at v valvular elements (Clap. & Lach,). 



36. Folliculina Boltoni, S. K., vol. ii. p. 600, x 200. 



37, 38. CHiETOSPiRA Muelleri, Lachmann, vol. ii. p. 602, extended and partially 

 retracted states as observed by the author, x 300. 



39. Folliculina hirundo, S. K., vol. ii. p. 600, x 200. 



40. Folliculina ampulla, Miiller sp., vol. ii. p. 597, var. viridis, Str. Wright, 



X 150 (Strethill Wright). 



