50 



Bashford Dean Memorial Volume 



Text-figure 1 Entire egg of Bddlostoma stout, including the capsule and anchor filaments. The 

 operculum is delimited by a circular groove situated a short distance below the animal pole. 



After Deay^, lo99. 



z 



Text-figure 2. This drawing of a portion of an egg of Bdellostoma stout, illustrates m greater detail the 

 structure of the anchor filaments and the opercular groove shown in text-figure 1 



After Dean, 1S99. 



Text-figure 3 Median longitudinal section through the animal pole of an egg of Bdellostoma stout.. 

 The opercular cap, a part of the egg-shell, is limited by the opercular groove. At the centre 

 of the group of filaments is the minute micropylar canal having above it a plug of mucus and 

 below It the germinal hillock. This latter is continuous with the protoplasmic mantle envelop- 

 ing the yolk which is arranged in concentric layers. 

 ^ ' After Dean, 1899. 



