64 Papers from the Department of Marine Biology. 



There are no teeth on the vomer, but on the tongue is a number of 

 rows of small, sharp-pointed recurved teeth which must materially 

 aid in the swallowing process, as do the large number of small teeth 

 covering the pharyngeals above and below and the inner edges of the 

 gill-arches. These are quite necessary, since the great barracuda 

 chops its prey (if of any size) into large fragments which are swallowed 

 whole. In addition to the structures described, there is a large breath- 

 ing valve in the upper jaw, just posterior to the four great canines and 

 anterior to the palatine teeth. Below, a similar structure is found 

 just in front of the tongue. The tongue has considerable freedom 

 of motion. 



On the under side of the lower jaw, just behind the point of junction 

 of the mandibles, are two round apertures leading into blind sacs 

 extending both backward and forward some little distance. What 

 function these subserve is not known to the writer. They are shown 

 in figure 6, plate ii. 



Before leaving this subject it may be of interest to give the sizes 

 of some of these great teeth. In fish No. 10 (3 feet 10 inches long), 

 the single tooth at the apex of the lower jaw measures 13 mm., the 

 big upper front teeth are 15 mm. long free of the gum, and the knife- 

 blade teeth implanted on the palatines run from 9 to 13 mm. The 

 large teeth of specimen No. 12 (55 inches long), which is No. iv of 

 the tables of teeth, have for the most part had their points broken off 

 and hence their measurements, generally speaking, do not show up 

 so large as they should. Thus the big lower tooth measures only 

 11 mm., while the upper ones run from 12 to 14 (tips broken) to 17 

 and 18 mm. (perfect teeth). The palatine teeth of this fish run from 

 9 to 16 mm. These measurements, it must be understood, are all made 

 from dried specimens and may possibly be slightly greater than in the 

 freshly caught fish. When the flesh was cleaned off of the fresh head, 

 on the lower jaw the big anterior tooth (tip broken) measured 10 mm. 

 and the great chopping teeth further back ran from 6 to 9 mm., aver- 

 aging about 7 to 8 mm. The great fangs of the anterior upper jaw 

 measured 11, 13 (two teeth), and 14 mm. (Two other teeth were 

 at the point of erupting.) The four great incisors on the right pala- 

 tine measured 12, 14, 8 (tip broken), and 10 nam. from before back- 

 ward. Similar measurements for the four corresponding teeth on the 

 left palatme were 12, 11, 11, and 9 mm. 



Figure 5, plate ii, shows the number and relative position of these 

 great teeth of the upper jaw. Some idea also can be gotten of the size, 

 shape, and position of those of the lower jaw. The photograph was 

 taken looking into the mouth from behind. The two mner groups of 

 teeth are the great fangs on the premaxillaries. The outer groups are 

 the huge knife-shaped teeth on the palatines. 



