100 University of California Puhlications in Zoology [Vol. 18 



Summary 



We conclude therefore on the basis of the examination of the evi- 

 dence from the comparative structure of Erythropsis and other Dino- 

 flagellata that the prod of Erythropsis is directed posteriorly, not ante- 

 riorly, that the girdle is anterior, not posterior in location, and that 

 the ocellus is directed anteriorly, not posteriorly. Likewise that the 

 transverse flagellum takes its origin at the anterior junction of girdle 

 and sulcus at the proximal end of the girdle and not at the attachment 

 area at its distal end. 



We also confirm Schiitt's (1896) findings as to the presence of a 

 posterior fiagellum in addition to the prod, arising in the chamber 

 about the base of that organ and projecting posteriorly. These con- 

 clusions from the standpoint of comparative anatomy are supported 

 by our observations on the locomotion of the living organism. Faure- j 



Fremiet's (1914) orientation of the animal with the prod anterior | 



and his account of the origin and course of the flagella must be rejected * 



as untenable. i 



» 

 Transmitted December 1, 1917. ' 



t 



ZooLOGiCAii Laboratory, ^ 



University of California, i 



Berkeley, California. 



