CYPRINOIDS. 147 



position to the entry of the CESophagus, and it may be seen how the 

 teeth must sift and lacerate the alimentary substances in their passage 

 through the pharynx. 



In the Gudgeon, (Gohio), which feeds on worms, aquatic larvse 

 and small moUusca, the pharyngeal teeth are conical, slightly curved 

 at the extremity and arranged in two rows. In the Acanthopsis, the 

 pharyngeal teeth are sharp-pointed and placed in a single row. In the 

 Loach, (Colitis), which feeds on aquatic larvse and worms, the pharyn- 

 geal teeth are slender and are chissel-shaped at the extremity. The 

 same scalpriform type is seen in the teeth of the genus Rhodeus. 



In the genus Schisothorax lately established by the laborious Ich- 

 thyologist I. J. Heckel for certain Cyprinoid Fishes from Cachmir, 

 the pharyngeal bones have three rows of teeth, two in the first, three 

 in the middle, and five in the third or posterior row, which last are the 

 strongest, all somewhat elongated, oblique, and with the extremity 

 slightly curved. The outer row of pharyngeal teeth are figured in situ, 

 on the right pharyngeal bone of the Schizothorax esocinus, Heck. (fig. 

 4) where they exhibit the shape most common in the genus : in Schi- 

 zothorax curvifrons, Heck, the pharyngeal teeth resemble long inverted 

 cones, the expanded, but originally pointed summits being soon worn 

 down so as to appear truncated. 



In the Cyprinus Nasus, L., similarly shaped teeth are arranged 

 in a single row, nine in number, on each pharyngeal bone ; the inferior 

 ones being somewhat larger, with a narrow but flat triturating surface, 

 supported upon a slender pedicle. 



In most of the species of Leuciscus, as the ide, the chub,(l) the 

 dobule, the dace, the minnow, and the roach, (fig. 4) the pharyngeal 

 teeth are subcorneal, slightly curved at the apex, and more or less 

 tinincated, in an oblique direction : their food, which includes the softer 

 parts of aquatic herbs with worms and insects in different stages, 

 corresponds with this approximation to the molar type. Some species 

 of Leuciscus, however, as the L. Scardinius, Bonap. have the pharyn- 

 geal teeth slightly dentated along the internal margin. The Leuciscus 

 erythrophthalmus has two rows of seven teeth on each pharyngeal bone ; 



(1) A friend informs me that the larger chub take the spinning minnow and gudgeon freely, 

 and mash them out of all shape. 



L 2 



