SENSE ORGANS OF AMIURUS. 2609 
tures in question is close. ‘They are small, hardly over 1 mm. iu 
size, und 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 ampulle 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.” 
