EXPLANATION OF PLATE XLV. 



STYLONYCHIA MYTILUS, Ehr., vol. ii. p. 790. Diagrammatic plan of oral ciliary 

 system : ad, adoral cilia or membranette; prcs, prasoral, and en, endoral 

 cilia ; , undulating membrane ; fr, frontal style (Sterki). 



2. GASTROSTYLA, sp. (Sterki). Diagrammatic optic section showing disposition of 

 the several ciliary systems ; d, dorsal, and m, marginal setae ; par, paroral 

 cilium ; the other lettering as in the preceding figure. 



3-5. OXYTRICHA PELLIONELLA, Mull, sp., vol. ii. p. 786. 3, Ventral aspect, x 400 ; 

 4, diagrammatic longitudinal section : ad, adoral, fr, frontal, v, ventral, an, 

 anal, and d, dorsal cilia or setae (after Sterki) ; 5, ventral aspect (after Stein). 



6. ACTINOTRICHA SALTANS, Cohn, vol. ii. p. 790, x 360 (Cohn). 



7. OXYTRICHA FALLAX, Stein, vol. ii. p. 787. Ventral aspect, x 170 (Stein). 



8, 9. OXYTRICHA PLATYSTOMA, Ehr. sp., vol. ii. p. 787. Ventral and dorsal aspects 

 X 300 (Stein). 



10-12. HISTRIO sp. (Sterki). 10, diagrammatic outline of zooid antecedent to sub- 

 division by transverse fission, showing at j, and s z the newly-growing 

 ventral ciliary series, at pr z , the second peristomal fringe, and at m\, m t , 

 the new elements of the first and second marginal series ; 1 1 and 12, showing 

 disposition and numerical order of development of the newly developing 

 frontal, ventral, and anal series (after Sterki). 



13, 14. HISTRIO STEINII, Miill. sp., vol. ii. p. 789. 13, Ventral aspect, x 200 ; 14, 

 example dividing by transverse fission, with at pr z and pr 3 newly 

 developing secondary and tertiary peristomal ciliary systems (Stein). 



15-17. STYLONYCHIA PUSTULATA, Ehr., vol. ii. p. 791. 17, Ventral aspect, x 150 ; 15, 

 zooid disintegrating by difnuence ; 16, encysted animalcule (Stein). 



18-21. STYLONYCHIA MYTILUS, Ehr., vol. ii. p. 790. 18 and 19, ventral and lateral aspects, 

 X 1 50 ; 20, zooid preparing to divide by transverse fission, the rudimentary 

 second peristomal fringe pr^ being already developed ; 21, variety having 

 the frontal, ventral, and anal styles and setae distinctly fimbriated (Stein). 



22. STYLONYCHIA FISSISETA, C. & L., vol. ii. p. 791. Ventral aspect, x 300 



(Claparede & Lachmann). 

 23, 24. ASPIDISCA LYNCASTER, Stein, vol. ii. p. 793- 23, Ventral and, 24, dorsal aspects, 



x 250 (Stein). 

 25-29. ASPIDISCA COSTATA, Duj. sp., vol. ii. p. 794. 25 and 26, ventral and dorsal 



aspects, x 300 (Stein) ; 27-29, developmental phases as observed by the 



author and described at p. 794. 



30. GLAUCOMA MARGARITACEUM, Ehr. sp., vol. ii. p. 796, x 150 (Clap. & Lach.) 

 31-33. ASPIDISCA TURRITA, C. & L., vol. ii. p. 793. Ventral, dorsal, and lateral aspects, 



x 209 (Stein). 



34-36. URONYCHIA TRANSFUGA, Mull, sp., vol. ii. p. 797. 34 and 35, Dorsal and ventral 

 aspects ; 36, example with fimbriated anal uncini, x 250 (Stein). 



37. MICROTHORAX SULCATUS, Eng., vol. ii. p. 796, x 22o (Engelmann). 



38-40, GLAUCOMA SCINTILLANS, Ehr., vol. ii. p. 795. 38 and 39, Ventral aspect, with at 

 39, vibratile membrane extended, x 150 ; 40, encysted zooid dividing by 

 oblique fission (Stein). 



