AMPHIDINIUBI OPERCULATUM AT PORT ERIN. 15 



to the coinings and goings oE such uiicroscopic forms and their physiological 

 inter-rehitions in connection with \vh:it may be called "the metabolism ol the 

 beach. '^—W. A. H. ■ 



Sept. 9th. — The Am.plddinium is now back again in abundanc c,and the 

 Diatoms are absent. — W. A. H. ■ 



EXPLANATION OF PLATE 8. 



Fig. 1. The general appearance of the brown deposits in the ripple-marks on the sand, 

 reduced in size. 



2. Sand-grains and Amplddinium (photo-micrograph under low-power magnification). 



3. Sketch from living preparation, to show some AmpJddbiia resting on the sand-grains 



and others swimming about (low power). 



4. Part of fig. 2 under high-power magnification. 



5. Dorsal and ventral views of Amphidinimn njjerculatinn — enlarged from high-powder 



magnification. 



For the photo-micrographs reproduced as figures 2 and 4, I am indebted 

 to my friend Mr. Edwin Thompson. 



LiNx, JoURN.— Zoology, vol. xXxil 



