548 PUOTOZOOLOGY 



F. leucas E. (Figs. 22, a, h; 250, a). 150- 600^ long; fresh water. 



F. hranchiostomae Codreanu (Fig. 250, b). 75-100/i by 55-95^*; 

 commensal in the branchial cavity of Amphioxus. 



Genus Disematostoma Lauterborn. Somewhat similar to 

 Frontonia; pyriform; with broadly rounded, truncate or concave 

 anterior end and bluntly rounded narrow posterior end; preoral 

 canal wide; a dorsal ridge in posterior region of body; macronu- 

 cleus sausage-form; a micronucleus; contractile vacuole in middle 

 of body toward left, with long collecting canals; in fresh water. 



D. hutschlii L. (Fig. 250, c). 135-155^ long; with or without 

 zoochlorellae; in fresh water. 



Genus Lembadion Perty. Oval ; dorsal side convex, ventral side 

 concave; cytostome 3/4-4/5 the body length; on its left with a 

 large membrane composed of many ciliary rows and on its right, 

 numerous narrow rows of short free cilia; an undulating mem- 

 brane and ciliary rows near posterior end; contractile vacuole in 

 mid-dorsal region with a long tubule opening at posterior-right 

 side; close ciliation uniform; macronucleus ellipsoid, subterminal; 

 a micronucleus; long caudal cilia; in fresh water. 



L. hullinum P. (Fig. 250, d). 120-200^ long; posterior cilia 40- 

 50/i long. 



Genus Glaucoma Ehrenberg {Dallasia Stokes). Ovoid or ellip- 

 soid; ventral surface more or less flattened; dorsal surface convex; 

 cytostome about 1/4 the body length from anterior end, oblong or 

 crescentic, with 3 undulating membranes; ectoplasmic ridge sur- 

 rounds cytostome; ciliation and striation uniform; macronucleus 

 rounded; a single micronucleus; with or without 1 or more caudal 

 bristles; a single contractile vacuole; fresh water. 



G. pyriformis E. (Fig. 250, e). Oval with short rounded anterior 

 end; contractile vacuole near posterior end; somewhat flattened; 

 cytostome near anterior end with a distinct membrane; cyto- 

 pharynx short; body 45-55ai by 30-40ai (Schewiakoff ) ; 38-80m 

 long (Kahl) ; in fresh water. This ciliate has been reported to in- 

 habit naturally and experimentally the body cavity of certain in- 

 sects (p. 27-28). 



G. frontata (Stokes). 65-140^ long; in fresh water. 



G. ficaria Kahl. 50-65m long; fig-like in form; a small ectoplas- 

 mic fringe; striae widely apart; contractile vacuole in posterior 

 1/5 and right-dorsal; in fresh water. 



Genus Lambornella KeiUn. EUipsoid; densely cihated; close 



