10 :i 

 Explanation of Figiirea. 



Fis. 1, ^:ewly-at taclied . .i'v.. ,. . ... f imbriata. Sketclied 

 from life. The foot is shown fully extended. x220. 



Fig. 2. Newly-attached larva, from the right side.- The 

 rir^ht shell, mantle and gills removed. The cells of the 

 disintegrating velum are not represented. The foot not fully 

 extended, x 320. 



Fig. 3. Young "Ship-worm" of about three days attach- 

 ment, from the ventral side. The shell is reprosented as 

 transparent, to shov;- the underlying gills on the sides of the 

 visceral mass, x 250. 



Fig. 4. Same stage as fig. 3, from the left side. The 

 left shell, mantle and gills represented as removed. The 

 double origin of the cerebral ganglion is still shown. The 

 visceral ganglion and kidney still lie in front of the pos- 

 terior adductor. The caecum fills the foot , and has crowded 

 the crystalline style and intestine to the loft side, x 250. 



Fig. 5. Specimen of about one v/eek in the wood. The 

 worm-like form is becoming rapidly assumed, x 190. 



.Fig, 6, Same stage as fig. 5, ventral vicvr. To show the 

 arrangement of the gills and the extent of t--'^ visceral mass. 

 X 190. 



Fig. 7. Same as fig. 5, the left sliell, mantle and gills 



