218 RIBAND-SKATED. 



teeth appear, two on each bone, somewhat within the margin : 

 the inner teeth do not exceed two lines in length. In the 

 lower jaw the teeth are placed nearer the outer margin, and 

 towards the front, four on one side, three on the other, with 

 some variation in size. A single-pointed tooth, three lines 

 in length, is placed vertically on the central line of the vomer, 

 but no other sharp teeth appear either behind this tooth, or 

 on the palatine bones, which, according to M. Valenciennes, 

 is the case in Tr. Falx. The superior pharyngeal bones are 

 studded with pointed curved teeth, one line in length ; the 

 inferior pharyngeal bones are wanting altogether. 



The large eyes, lodged in a circular orbit, are situated near 

 the frontal profile. The longitudinal diameter of the orbit 

 is, compared to the length of the head, as one to three and a 

 half; the iris is silvery white, its breadth somewhat greater 

 than the diameter of the pupil. 



The nostrils are very small, opening into narrow cavities, 

 situated above the anterior and superior part of the orbital 

 margin ; the larger nostril, a small rima, is situated close 

 upon the margin ; the smaller one is oval, and is placed a 

 little higher up. 



The anterior extremity of the tongue is somewhat broad, 

 with a rounded margin, concave above, flat and keeled under- 

 neath ; the tongue is entirely free, and may easily be placed 

 in a horizontal position, as if intended to throw small bodies 

 towards the pharynx. 



The lateral line, commencing from the nuchal region, de- 

 scends nearly vertically opposite the middle of the orbit, from 

 whence it proceeds obliquely downwards, until behind the 

 pectoral fin, it reaches a distance from the ventral profile 

 somewhat shorter than the distance of the dorsal profile. It 

 now continues straight towards the extremity of the tail, 

 approaching the lower caudal margin. This line is covered 

 by a series of small oblong osseous shields, from the middle 



