94 SAND-SHARK. 



LATERAL LINES AND MUCIFEROUS OPENINGS. 



The lateral lines, united by a transverse line posterior 

 to the orbits, are distinctly marked on each side of the 

 body from the snout to the tail. Pin-hole like mucus 

 openings thickly cover the snout and head and to a less 

 extent the entire surface of the body. 



EYES. 



The eyes, without nictitating membrane, are small, 

 seven and one half inches from the end of the snout, three 

 inches above the mouth, with an inter-orbicular space of 

 seven inches. 



Irides silvery -gray, pupillary openings small and black. 



NOSTRILS. 



The nostrils, midway between the orbits and the end 

 of the snout, are oblong and not confluent with the 

 mouth. 



MOUTH AND JAWS. 



The mouth is inferior, wide, with the shape of the let- 

 ter U. The upper jaw is eight and one half inches long, 

 on the dental margin, and eight inches wide ; the lower 

 jaw is six and one half inches long and seven inches 

 wide. 



Dental formula- Rff L - 2 -H°P- 4 = ^ T °f". 



The teeth in front are long, subulate and curved in- 

 ward, with basal cusps. The first tooth on either side of 

 the median line in the lower jaw, and the fourth tooth 

 on either side in the upper jaw are very small, — project- 

 ing sharp points, — without basal cusps. 



In the posterior part of each jaw there are six visible 

 rows of teeth, but, the last ten of each row are so small 

 and so crowded together, that they appear like a single 

 tuberculated tooth. 



In front two full rows of teeth in each jaw are fully 



-as 



