HOLOTRICHA 739 



Genus Mycterothrix Lauterborn (Trichorhynchus Balbiani). An- 

 terior cone continuous on dorsal side with body ridge; hence free edge 

 of body only on ventral side; no ventral slit. 



M. erlangeri L. (Fig. 314, c). Nearly spherical with zoochlorellae; 

 50-55ju by 40-50^; fresh water. 



Family 2 Trichopelmidae Kahl 



Genus Trichopelma Levander (Leptopharynx Mermod). Com- 

 pressed; surface with longitudinal furrows, seen as lines in end-view; 

 coarse ciliation throughout; cytostome toward left edge about 1/3 

 from the anterior end; cytopharynx tubular; macro nucleus spheroid, 

 central; 2 contractile vacuoles; fresh water. 



T. sphagnetorum (L.) (Fig. 314, d). 25-40/x long; in fresh water. 



Genus Pseudomicrothorax Mermod (Craspedothorax Sondheim). 

 More or less compressed; cytostome opens in anterior half toward 

 left side, in a depression surrounded by ciliary rows; body surface 

 marked with a broad longitudinal ridge with cross striation; furrows 

 canal-like; cilia on ventral side; cytopharynx tubular, with elastic 

 rods ; fresh water. 



P. agilis M. (Fig. 314, e,f). Ellipsoid ; 48-58ju long; in fresh water. 



Genus Drepanomonas Fresenius (Drepanoceras Stein). Highly flat- 

 tened; aboral surface convex; oral surface flat or concave; with a few 

 deep longitudinal furrows; ciliation sparse; cytostome and a small 

 cytopharynx simple, near the middle of body; fresh water. Several 

 species. 



D. dentata F. (Fig. 314, g). With a small process near cytostome; 

 2 rows of ciliary furrows on both oral and aboral surfaces; cilia on 

 both ends of oral surface; 40-65/z long; in fresh water. 



Genus Microthorax Engelmann (Kreyella Kahl). Small, flattened; 

 with delicate keeled armor which is more or less pointed anteriorly 

 and rounded posteriorly; ventral armor with 3 ciliary rows; oral de- 

 pression posterior-ventral, with a stiff ectoplasmic lip on right side, 

 below which there is a small membrane, and with a small tooth on 

 left margin; no cytopharynx; macro nucleus spherical; 2 contractile 

 vacuoles; in fresh water. Many species. 



M. simulans Kahl (Fig. 314, h). 30-35ju long; decaying plant infu- 

 sion, also in moss. 



Family 3 Trimyemidae Kahl 



Genus Trimyema Lackey (Sciadostoma Kahl). Ovoid, more or less 

 flattened; anterior end bluntly pointed, posterior end similar or 

 rounded; with a long caudal cilium; cilia on 3-4 spiral rows which are 



