NURSING ARRANGEMENTS OF A RAY. 



Fig. 4. — Lower part of the oviduct of the Indian Bat-ray {Pteroplativa 

 micrura\ laid open to show the unborn young one, and the filaments by the 

 secretion of which the latter is nourished. A large bundle of filaments passes 

 through each spiracle into the pharynx of the immature fish. 



\To face page 72. 



