HOLOTRICHA 565 



2 closely arranged rings of long cilia; anterior ring made up of some 

 60 pectinelles which are directed anteriorly; posterior ring composed 

 of about the same number of long cilia directed posteriorly and 

 arranged parallel to body surface; fresh or salt water. 



A. faurei Kahl (Fig. 268, n). Body oval, anterior end broadly 

 rounded; posterior region conical; pectinelles about 13^ long; the 

 second band (lOju) of long cilia; an ellipsoid macronucleus ; a micro- 

 nucleus; body about 58-60/x long; fresh water. 



Genus Cyclotrichium Meunier. Body spheroid to ellipsoid with a 

 large non-ciliated oral field which is surrounded by a pectinelle-ring, 

 the remaining part naked or slightly ciliated; macronucleus sausage- 

 form; cytopharynx not recognized; endoplasm highly vacuolated; in 

 marine plankton. 



C. meunieri Powers (Fig. 268, o). Anterior end broadly rounded; 

 posterior region conical; cytostome obscure; oral funnel at ante- 

 rior end in a depression; broad ciliated band at about middle; ecto- 

 plasm with concave chromatophore (covered with haematochrome) 

 plates on surface, below which numerous pyrenoids occur in vacu- 

 oles; endoplasm with numerous granules; 25-42/x by 18-34ju; Powers 

 (1932) found that the 'red water' in Frenchman Bay in Maine was 

 caused by the swarming of this organism. 



Family 4 Colepidae Claparede and Lachmann 



Genus Coleps Nitzsch. Body-form constant, barrel-shaped; with 

 regularly arranged ectoplasmic plates; cytostome at anterior end, 

 surrounded by slightly longer cilia; often spinous projections at or 

 near posterior end; 1 or more long caudal cilia, often overlooked; 

 fresh or salt water. Many species. 



C. Urtus (Miiller) (Fig. 269, a). 40-65^ long; 15-20 rows of plate- 

 lets; 3 posterior processes; fresh water. 



C. elongatus Ehrenberg (Fig. 269, h). 40-55^ long; slender; about 

 13 rows (Noland) or 14-17 rows (Kahl) of platelets; 3 posterior 

 processes; fresh water. 



C. bicuspis Noland (Fig. 269, c). About 55m long; 16 rows of plate- 

 lets; 2 posterior processes; fresh water. 



C. octospinus N. (Fig. 269, d). 80-1 10m long; 8 posterior spines; 

 about 24 rows of platelets; Geiman (1931) found this organism in an 

 acid marsh pond and noted variation in number and location of ac- 

 cessory spines; fresh water. 



C. spiralis N. (Fig. 269, e). About 23 longitudinal rows of platelets 

 slightly spirally twisted; posterior spines drawn together; a long 

 caudal cilium; about 50m long; salt water; Florida. 



