218 

 a 



PROTOZOOLOGY 

 c d 



Fig. 100. a, Prorocentnim micans, X420 (Schiitt); b, c, Exuviaella 

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

 f, Glenodinium cinctuni, X590 (Schilling); g, G. j)ulvisculum, x420 

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

 (Schilling); j, G. negleduni, X650 (Schilling). 



Suborder 1 Prorocentrinea Poche 



Test bivalve; without any groove; with yellow chromato- 

 phores; 2 flagella anterior, one directed anteriorly, the other vi- 

 brates in a circle; fresh or salt water. 



Family Prorocentridae Kofoid 



Genus Prorocentrum Ehrenberg. Elongate oval; anterior one 

 bluntly pointed, with a spinous projection at pole; chromato- 

 phores small, yellowish brown; salt water. 



P. micans E. (Fig. 100, a). 36-52/x long; a cause of "red water." 

 P. triangulatum Martin. Triangular with rounded posterior 

 end; shell-valves flattened; one valve with a delicate tooth; sur- 

 face covered with minute poroids; margin striated; chromato- 

 phores yellow-brown, irregular, broken up in small masses; 17- 

 22/i (excluding tooth); Martin found it extremely abundant in 

 brackish water in New Jersey. 



