HOLOTRICHA 



575 



contracted pellicular striae not spiral and no neck as is the case with 

 Chaenea; salt water. Many species. 



T. phoenicopterus Cohn (Fig. 273, d, e). Elongate; extensible and 

 contractile; neck and tail distinct when contracted; cytostome at 

 anterior end, surrounded by a ridge containing indistinctly visible 

 short trichocysts, cytopharynx with trichocysts; macronuclei made 

 up of 4 radially arranged endosomes suspended in the nucleoplasm 

 (Gruber, KahJ); micronucleus difficult to make out; contractile 



Fig. 273. a, Rhopalophrya salina, X870 (Kirby); b, Ileonema dispar, 

 Xl60 (Stokes); c, /. ciliata, X670 (Roux); d, e, Trachelocerca phaenicop- 

 terus (d, XlOO; e, anterior end, X220) (Kahl); f, g, T. subviridis (f, Xl30; 

 g, nucleus, X400) (Noland); h, Parachaenia myae, X670 (Kofoid and 

 Bush). 



vacuoles apparently in a row, rarely seen; salt water; Woods Hole 

 (Calkins). 



T. subviridis Sauerbrey (Fig. 273,/, g). Highly extensible and con- 

 tractile; nucleus contains peculiar crystal-like bodies; size variable; 

 when extended 320-480/^ long; salt water. Noland observed the or- 

 ganism in a salt spring in Florida, 



Genus Parachaenia Kofoid and Bush. Small; compressed; ventral 

 surface slightly concave; dorsal surface greatly convex; cilia long. 



