146 CYPRINOIDS. 



of the skull), arising from the outer margin of the anterior and 

 inferior moiety of the pharyngeal bone, passes inwards below the 

 pharynx and expands to meet its fellow at a strong median raphe. 

 This muscle, which is more especially developed in the barbel, 

 p-udgeon, and those Cyprinoids which have the teeth formed for 

 piercing and lacerating, besides approximating the pharyngeal bones 

 at the median line, at the same time draws them forwards. The 

 antagonist muscle (c) arises from the descending spine of the basi- 

 occipital bone, and passing outwards and forwards, expands to be 

 inserted along the outer margin of the posterior half of the pharyngeal 

 bone ; this muscle while it draws back the pharyngeal bones, at the 

 same time, from the mode of attachment of the bones to the skull, 

 slightly divaricates them. 



The teeth are attached to the inner side of the pharyngeal bones 

 by a confluence of their basis with the osseous substance. It might be 

 supposed that the food of the leather-mouthed fishes, as the Cypri- 

 noids without maxillary teeth are commonly termed, would be so 

 nearlv the same, that the few teeth which were lodged in the fauces 

 would present much sameness of form ; but this is by no means the 

 case, as the selection of pharyngeal teeth from the Cyprinoid genera 

 figured in plate 57 demonstrates. The laniary type is best shown 

 in the barbel (fig. 1 & 2) and the molary type in the carp (fig. 6 k 7) ; 

 indeed, the large lower 'pharyngeal tooth of this species exhibits, 

 before it is too much worn, the most complicated triturating surface 

 of any single tooth in the osseous fishes, and one w^hich most closely 

 resem.bles that of the molars of certain herbivorous mammalia. (1) 



The barbel {Barbus vulgaris), which feeds on slugs, worms and 

 small fishes, requires teeth so shaped as to pierce and lacerate the skin 

 of its prey, and to tear them into fragments capable of passing the 

 narrow oesophagus : in this species they accordingly are elongated, coni- 

 cal, slightly and somewhat irregularly bent, arranged in three rows, and 

 increasing in number and size from the innermost to the outermost row ; 

 the teeth in this row are generally five in number, separated by inter- 

 spaces, so as to interlock, when the pharyngeal bones are approximated, 

 as represented in plate 57, fig. 1 ; the probe (a) shows their relative 



(1) " In the carp, the crowps of the teeth are observed to be so worn down as to have the 

 appearance of the crowns of the molar teeth of the hare." — Yarrell, 1. c. Introduction, p. xix. 



