SENSE ORGANS OF AMIURUS. 269 



tures in question is close. " They are small, hardly over 1 mm. in 

 size, and are especially numerous on the under surface of the snout, 

 round the eyes, and on the occipital and opercular regions. In the 

 form of the histological elements they recall the ampulla? of the 

 Selachians more than the nerve-hillocks of the Teleosts. The epider- 

 mis of the skin is folded into a minute sac, in the interior of which 

 the stratified pavement epithelium gives place to a single layer of 

 cylindrical epithelium with a distinct cuticle. Between the cylin- 

 drical cells are found the hair-bearing sensory cells, shaped like those 

 of the Teleosts, but closer together, as well as shorter and more 

 pointed. Below each sac is a subcutaneous cavity filled with gela- 

 tinous substance." 



