THE PHARYNGEAL TEETH OF FISHES. 191 



Mugil braziliensis frequents the eastern coast of South 

 America. The specimen examined came from Demerara, where 

 it is called the " Queeriman." The gill-rakers are very 

 numerous in this fish ; from the top of the epibranchial to the 

 extremity of the hypobranchial there are 146. In the centre of 

 this length they run forty-five per inch ; they are rather closer 

 together at the extremities. They are fairly long, but are only 

 in length one-third of the depth of the gill-laminfe below them. 

 The gill-laminae in this fish, however, are very long. The inner 

 edges of the gill-rakers carry a number of minute bristles. 

 There are numerous gill-rakers on the inner and outer faces of 

 the other arches ; they slope over to meet each other, and their 

 extremities touch in a well-defined line. The filter formed is a 

 very close one. The faces of the pharyngeal bones are very 

 much curved, the lower one being curved with long gill -rakers 

 lying all across it. The mucous membrane of the upper 

 pharyngeal bones has, as stated before, numerous cilia-like 

 processes that evidently would help in separating edible 

 organisms when undergoing the triturating action that the 

 structure of the upper and lower pharyngeal bones seems so 

 adequately adapted to perform. 



Mugil capito, the Grey Mullet, has numerous — one hundred or 

 more — horny gill-rakers on the first cerato-hypobranchial, the 

 longest about half the depth of the gill-laminse below it ; there 

 are seventy-two on the first epibranchial. The inside of the 

 first, both sides of the second, and the outside of the third arches 

 have a number of similar but shorter gill-rakers very closely set, 

 and these form a very efficient filter. The inside of the third 

 and outside of the fourth have an edging of still shorter gill- 

 rakers. The gill-rakers are very brittle ; their inner edge is 

 serrated. The upper pharyngeal bone in this, as in the rest of 

 the Mugilidce, is quite differently formed structurally from this 

 bone in other fishes. The mucous lining of the upper pharyngeal 

 bone is similar to that of the last described fish. 



CHiETODONTID^. 



Heniochus macrolepidotus, from the Indian Ocean. The 

 gullet of this fish is very small, and the gill-rakers minute. 

 No pharyngeal teeth could be seen or felt in either upper or 



