HOLOTRICHA 499 



L. hellerophon Penard (Fig. 229, I). 100-180^; fresh water. 



Genus Teuthophrys Chatton et Beauchamp. Body rounded 

 posteriorly, anterior end with 3 radially equidistant, spirally 

 curved arms (counter-clockwise when viewed from posterior end) ; 

 the depressions between arms form furrows; cytostome apical, at 

 the inner bases of arms; contractile vacuole terminal; cihation 

 uniform, except the inner surfaces of arms where longer ciha as 

 well as trichocysts are present; with zoochlorellae; macronucleus 

 rope-shaped and wound; micronucleus unobserved. One species. 



T. trisnla C. et B. (Fig. 230, a). 150-300^ long; length: width 

 3 : 1-2 : 1 ; ponds in Pennsylvania and California (Wenrich). 



Family 2 Metacystidae Kahl 



Genus Metacystis Cohn. Oblong; definite; ciliation general, 

 except posterior end; ciliary circle around cytostome; usually one 

 caudal cilium; with a large posterior vesicle containing turbid 

 fluid. 



M. truncata C. (Fig. 230, h). Elongate, not much difference in 

 body width at different levels; with about 12 furrow rings; body 

 length up to 30^; salt water. 



Genus Vasicola Tatem (Pelamphora Lauterborn). Ovoid with 

 caudal cilia; lorica flask-shape, highly ringed; cytostome at an- 

 terior end, its lip with 4 rows of long ciha; body surface with short- 

 er cilia; macronucleus round, central, with a micronucleus; con- 

 tractile vacuole near macronucleus and nearer body surface; 

 fresh or salt water. 



V. ciliata T. (Pelamphora butschlii Lauterborn) (Fig. 230, c). 

 Body about 100/x long; sapropelic in fresh water. 



Genus Pelatractus Kahl. Somewhat similar to Vasicola; but 

 without caudal cilia; with a large terminal vacuole; without lip 

 of Vasicola; sapropelic. 



P. (Vasicola) grandis (Penard) (Fig. 230, d). Free-swimming; 

 elongated fusiform; numerous contractile vacuoles on side; body 

 1 25-220^1 long ; sapropelic in fresh water. 



Family 3 Didiniidae Poche 



Genus Didinium Stein (Monodinimn Fabre-Domergue). Bar- 

 rel-shaped; one to several girdles of cilia (pectinellae) ; expansible 

 cytostome at tip of cone-like elevation at anterior end, containing 

 long trichites; macronucleus horseshoe-shaped; contractile vacu- 



