DINOFLAGELLATA 219 



Genus Exuviaella Cienkowski. Subspherical or oval; no anterior 

 projection, except 2 flagella; 2 lateral chromatophores, large, 

 brown, each with a pyrenoid and a starch body; nucleus posterior; 

 salt water. Several species. 



E. marina C. (Fig. 100, h, c). 36-50/i long. 



E. apora Schiller. Compressed, oval; striae on margin of valves; 

 chromatophores numerous yellow-brown irregular in form; 30- 

 32m by 21-26m (Schiller); 17-22/z by 14-19; (Lebour; Martin); 

 common in brackish water. New Jersey. 



Suborder 2 Peridiniinea Poche 



Typical dinofiagellates with one to many transverse annuli and 

 a sulcus; 2 flagella, one of which undergoes a typical undulating 

 movement, while the other usually directed posteriorly. Accord- 

 ing to Kofoid and Swezy, this suborder is divided into two tribes. 

 Body naked or covered by a thin shell . . . Tribe 1 Gymnodinioidae 



Body covered by a thick shell Tribe 2 Peridinioidae 



(p. 229) 



Tribe 1 Gymnodinioidae Poche 



Naked or covered by a single piece cellulose membrane with 

 annulus and sulcus, and 2 flagella; chromatophores abundant, 

 yellow or greenish platelets or bands; stigma sometimes present; 

 asexual reproduction binary or multiple division; holophytic, 

 holozoic, or saprozoic; the majority are deep-sea forms; a few 

 coastal or fresh water forms also occur. 



With a cellulose membrane Family 1 Cystodiniidae 



Without shell 



Furrows rudimentary Family 2 Pronoctilucidae (p. 220) 



Annulus and sulcus distinct 

 Solitary 



With ocellus Family 3 Pouchetiidae (p. 220) 



Without ocellus 



With tentacles Family 4 Noctilucidae (p. 222) 



Without tentacles 



Free-living Family 5 Gymnodiniidae (p. 223) 



Parasitic Family 6 Blastodiniidae (p. 227) 



Permanently colonial Family 7 Polykrikidae (p. 228) 



Family 1 Cystodiniidae Kofoid et Swezy 

 Genus Cystodinium Klebs. In swimming phase, oval, with ex- 



