EXPLANATION OF PLATE XXIX. 

 Fro. 



1-2. BURSARIA TRUNCATELLA, Muller, 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.— «;/, 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. CONDYLOSTOM.A. STAGNALE, Wrz., vol. ii. p. 584, X 150. — u, Undulating mem- 



brane (Wrzesniowski). 



12. CoNDYLOSTO.MA PATENS, Mull, sp., vol. ii. p. 584, X 150 (Stein). 



13, 14. Spirostomum ambiguum, Ehr., vol. ii. p. 5S6. — 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 1 2l second peristome (Stein). 



18. Leucophrys patula, Ehr. sp., vol. ii. p. 587, x i^o.^h, phar>'ngeal 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 are entirely withdrawn, leaving the stylate appendage only projecting beyond 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, Muller 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 tiaiitiloidcs, 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. Ch^tospira 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, MiiUer sp., vol. ii. p. 597, var. VIRIDIS, Str. Wright, 



X 150 (Strethill Wright). 



