PHARYNGEAL TEETH OF FISHES. 



265 



Notopterus chitala, a fish found in the rivers of India, has 

 eight long horny gill-rakers with two rudimentary ones on the 

 first cerato-hypobranchial and three on its epibranchial. They 

 all bear teeth. The longest equals in its length the depth of the 

 gill-larnina3 below it. The one at the angle is very short. 

 Similar but smaller gill-rakers are on the other arches, they get 

 shorter as they belong to the more inward arches. The in sides 

 of the arches have short upstanding gill-rakers fitting into the 



Fig. I. 



1. — Albula conoehynchus. 



2. — Notopterus afer. 



opposite ones and making a good filter. The upper pharyngeal 

 teeth are represented by a small group of minute cardiform teeth 

 on the heads of the third and fourth epibranchials. The lower 

 pharyngeal teeth are in two long plates of minute cardiform 

 teeth. A long plate of minute villiform teeth covers the forward 

 basibranchials. There are five backwardly curved teeth along 

 each edge of the tongue, with one at the tip with sharp points. 

 This one and the next two on each side are strong, the other 

 three each side are smaller. At the base of the tongue and 

 lying between the marginal is a group of short but strong 



