SCOMBEROIDS. 125 



armed with a group of three very large, slightly recurved, lancet- 

 shaped teeth, placed in a triangle, of which the apex is directed 

 forwards ; then on each side there is a single lancet-shaped tooth, 

 about half the size of the preceding, and behind these, there is a row 

 of seven smaller and close-set teeth. The lower jaw has a pair of 

 long sub-conical teeth in front, one on each side, with a smaller one 

 between them ; and below these, on the outer side of the symphysis, 

 there is a single conical tooth projecting forwards. Behind the first 

 pair of teeth, there extends along each ramus of the jaw a row of 

 five much smaller teeth, followed by tliree rather larger, which become 

 gradually more compressed ; then there are two lancet-shaped teeth, 

 considerably larger, which lock into the interval in the upper jaw^, and 

 after a short diastema follows a row of eleven short but broad and 

 compressed teeth. All these teeth, when fully formed, are firmly 

 anchylosed by their bases to depressions in the jaw bones. 



In all the Scomberoid fishes the succession of teeth is unin- 

 terrupted ; the pulps of the new teeth are developed in most of 

 the species in the soft gum or integument covering the denti- 

 gerous margins of the bones, and the calcification of the pulp is 

 completed as it lies recumbent and buried loosely in the substance 

 of the gum. The point of the new tooth, which, in this state, is 

 directed backwards, is then exposed by a gradual rotatory move- 

 ment of the tooth from the horizontal to the vertical position ; the 

 jaw^ bone grows around its base, and, ossification proceeding along 

 the ligamentous attachment of the tooth, finally fixes it to the jaw by 

 continuous anchylosis. 



In a large exotic Trichiurus, I find six large barbed fangs at the 

 anterior part of the upper jaw, three recumbent and loose, and three 

 erect and fixed. These are situated alternately, so that in one 

 specimen two of the fixed teeth may be im.planted in the right, and 

 one opposite the interspace of the preceding, in the left palatine bone; 

 while in another specimen the situation of the fixed teeth is reversed, 

 as is also that of the recumbent and loose successional teeth. (1) 



(1) The discovery of the larger teeth, lying loosely in the gum, near the base of the fixed teeth 

 they are destined to supplant, is apt to occasion surprise in those, who may not be acquainted 

 with their mode of development. Thus, the excellent Ichthyologist from whose description 



