DINOFLAGELLATA 247 



Family Prorocentridae Kofoid 



Genus Prorocentrum Ehrenberg. Elongate oval; anterior end 

 bluntly pointed, with a spinous projection at pole; chromatophores 

 small, yellowish brown; salt water. 



P. micans E. (Fig. 106, a). 36-52jli long; a cause of "red water." 

 P. triangulatum Martin. Triangular with rounded posterior end; 

 shell-valves flattened; one valve with a delicate tooth; surface cov- 

 ered with minute pores; margin striated; chromatophores yellow- 



FiG. 106. a, Prorocentrum micans, X420 (Schiitt); b, c, Exuviaella 

 marina, X420 (Schiitt); d, e, Cystodinium steini, X370 (Klebs); f, Gleno- 

 dinium cinctum, X590 (Schilling); g, G. pulvisculum, X420 (Schilling); 

 h, G. uliginosuvi, X590 (Schilling); i, G. edax, X490 (Schilling); j, 

 G. neglectum, X650 (Schilling). 



brown, irregular, broken up in small masses; 17-22/i (excluding 

 tooth); Martin found it extremely abundant in brackish water in 

 New Jersey. 



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. 106, b, c). 36-50^ long. 



