CILIATA. 49 



cilia at edge of bell leading to mouth at base of appendage. CeenomorpJia 

 Perty, f.w. and in. 



Section 2. Oligotricha. 



Never elongated, usually spherical or conical. Peristomial field at front end 

 and at right angles to the long axis. Adoral row nearly or completely a closed 

 circle. Ciliation of body partly well developed, partly much reduced. 



Fam. 1. Lieberkuhnina, possibly a young form of Stentor. 



Fam. 2. Halterina. Peristomial surface without cilia. Body with few 

 scattered or no cilia : sometimes with scattered immovable setaj. No shell. 

 Strombidium Cl. and L., f.w. and m. ; Haltcria Duj., f.w. 



Fam. 3. Tintinnoina. Provided with a tubular shell, to the base of which 

 the body is fastened by a stalk. Adoral row as a circle of large membranellae, 

 inside which is a row of fine cilia (paroral). Tintinnidium Kent, f.w. and m.; 

 Tintinnus Schrank, m. ; Tinlinnopsis Stein, m. ; Codonella Hack., f.w. and m. ; 

 Dictyocysta Ehrb., m. 



Fam. 4. Ophryoscolecina, with thick pellicle, hinder end often with spine- 

 like processes, deep funnel-shaped peristomial region. Anus terminal, usually 

 with anal tube. Parasitic in rumen of Ruminants. Entodinium Stein ; 

 Diplodinium Schuberg ; Ophryoscolex Stein. 



Section 3. Hypotricha. 



Body dorso-ventrally flattened, ventral surface usually flat, dorsal convex ; 

 peristomial field usually triangular and in same plane as rest of ventral surface. 

 Dorsal surface without cilia, but with stiff bristles. The ventral cilia uniform or 

 in various ways reduced and differentiated. Pharynx little developed or absent. 



Fam. 1. Peritromina. Peristome but little marked off from frontal area. 

 Ciliation of ventral surface close and uniform without differentiation of stronger 

 cilia or cirri. Peritromus Stein, m. and f.w. 



Fam. 2. Oxytrichina. Peristome distinctly marked off from frontal area. 

 Ventral ciliation in the most primitive forms uniform in oblique longitudinal 

 rows ; but some stronger cilia are almost always present on the frontal area 

 (frontal cirri) and at the hind end (anal cirri). Usually the ventral cilia are 

 cirri. A right and left row are distinguished as marginal cirri from the 

 imperfect median rows which are called ventral cirri (Fig. 41). These rows of 

 cirri must not be confused with the adoral row of membranellse (a.) on the left 

 side of the peristome. There is an undulating membrane on the right side of 

 the peristomial area (the preoral membrane, Fig. 41 TO.), and in many forms a 

 row of cilia on the right side of the adoral row (the paroral row, Fig. 41 b) ; 

 both these structures are, like the adoral row, continued into the pharynx. 

 Trichogaster Sterki, f.w.; Urostyla Ehrb., f.w. and m. ; Kerona Ehrb., com- 

 mensal on Hydra; Epiclintes Stein, m. ; Stichotricha Perty, f.w. and m. ; 

 Strongylidium Sterki, f.w.; Holosticha Wrzesn., m. ; AmpMsia Sterki, f.w. and 

 m. ; Uroleptus Ehrb., f.w. and m. ; Onychodromus Stein (Fig. 41), f.w.; Pleuro- 

 triclia Stein, f.w.; Gastrostyla Engelm., f.w.; Gonostomum Sterki, f.w. and m.; 

 Urosoma Kowalewsky, f.w.; Oxytricha Ehrb., f.w. and m. : Stylonychia Ehrb. 

 (Fig. 30), f.w. and m. ; Actinotricha Cohn, m.; Balladina Kow., f.w.; Psilotricha 

 Stein, f.w. 



Fam. 3. Euplotina. Ciliation much reduced ; the anal cirri are always 

 present, but the marginal frontal and ventral cirri may be absent ; encuirassed. 

 J-htplotes Ehrb., f.w. and m. ; Diophrys Duj., m. ; Uronychia Stein, m. ; Aspidisca 

 Elirb. (Fig. 42), f.w. and m. 



E 



