-MARINE BIOLOGICAL STATION AT PORT ERIN. 53 



lias been denied by some previous writers. The two 

 characteristic Dinoflagellate grooves certainl}^ join, as 

 is stated by Calkins, but not by other observers. The 

 posterior flagellum which projects freely from the body 

 is not diflBcult to see, but the anterior one which lies 

 along the transverse groove is not so easy to demonstrate, 

 and may differ a little in position and extent from what 

 is shown in the figure. Stages in longitudinal fission 

 were frequently seen, and that is probably the commonest 

 method of reproduction. What appeared to be con- 

 jugation between two individuals was observed by Miss 

 Latarche in one instance. 



/ / 



/ 



Fig. 26. Dorsal and ventral views of Amphidiniumoperculatum — enlarged 

 from high-power magnification. 



" It may be that this organism lives normally in 

 small quantities, so as not to be conspicuous, in some 

 region of the sand}^ beach, or possibly in some special 



