Sphyrcena barracuda; its Morphology, Habits, and History. 65 



Inspection of figures 12 and 13, plate iv, shows that the teeth are 

 set in alveoli or sockets in each ramus of the mandible and the pre- 

 maxillary, and in each palatine. These teeth are polyphydont that 

 is, they are replaced by new teeth as soon as they are worn down, 

 broken off, or become loosened in their sockets. In some socketed 

 teeth the succession is vertical, i. e., the new tooth is formed in the 

 same socket as the old one and grows out at the same aperture. This 

 is by virtue of the fact that the base of the old tooth is absorbed and 

 the new tooth thus comes to lie below it and to take its place. In 

 other fishes the new tooth succeeds its predecessor, growing side by 

 side with it or its stump. 



In the great barracuda the teeth are set in sockets, out of which 

 they grow by multiplication of cells at their pulpy bases. Room for 

 the new teeth is often made by the old teeth being broken off, where- 

 upon the root is resorbed and a new tooth erupts alongside the first 

 to take its place. This state of things can be seen in the photographs 

 of the skull of the specimen from Miami, as shown in figures 12 and 

 13, plate iv. In the figure of the lower jaw, the fang at the terminus 

 of the left ramus has been broken off and already one sees the chink 

 through which the new tooth will emerge. In figure 12, of the upper 

 jaw, we have a similar state of affairs. The left front fang has been 

 broken off, the one next to it has become loose in its socket and in the 

 space between the two is seen the hole out of which the new tooth will 

 come. 



Closer inspection of figures 12 and 13, plate iv, will show some two 

 dozen similar cases among the premaxillary, mandibular, and pala- 

 tine teeth. All stages can be made out from the recently broken-off 

 stumps to the half-grown replacing tooth. This is the reason for the 

 variable number of great fangs at the apex of the upper jaw. Some of 

 these in the cleaned head, it should be noted, were so loose in their 

 sockets that they had to be glued in to prevent their being lost. A 

 similar state of affairs is revealed by a close examination of the jaws 

 of the three dried heads. The study of the succession of teeth in this 

 fish would be of both interest and value. It would, however, have to 

 be undertaken where there was an abundance of fresh material. 



Before taking up the literature of this phase of the subject it is 

 well to emphasize the fact that all my specimens and their figures 

 show but one fang at the symphysis of the lower jaw. For this see 

 the figures of the dried heads on plate in; and figure 13, plate iv, 

 showing the teeth of the fresh specimen from Miami. These single 

 fangs are always inclined toward the median line, the ones situated 

 on the right side are inclined towards the left, and vice versa. Inspec- 

 tion of the largest dried head and of the fresh specimen, however, 

 shows that the left tooth has only recently been broken off; while in 



