SMALL-SPOTTED DOG-FISH. 371 



two teeth formed for cutting; these are flattened, thin, sharp, 

 and serrated on both edges ; the teeth represented belong to 

 the left of the centre when viewed in front. The two teeth 

 on the right hand are formed for holding, being generally 

 curved inwards, and provided with a small lateral tubercle at 

 the base on each side. The teeth of the Sharks belonging 

 to the genus Scyllium, now under consideration, are of this 

 last form, but smaller, depending on the size of the fish. 

 The outside tooth in the front row of each jaw in the Sharks 

 is supported on the inside by various other teeth, which sup- 

 ply deficiencies as necessity may require. 



The specimen from which the description was taken mea- 

 sured eighteen inches in length ; the body, from the base of 

 the pectoral fins, where it is thickest, tapering all the way to 

 the end of the tail. The head is flattened on the top ; the 

 eyes large ; the orbits elongated, with a distinct aperture 

 behind each ; the form of the under surface of the nose, the 

 nostrils, and upper lip, as shown in the left-hand figure of 

 the vignette at the end ; the mouth in the form of a horse- 

 shoe, the extreme angles only being directed outwards ; the 

 teeth numerous, small, pointed, and sharp, like those on the 

 right hand in the representations of Shark's teeth, but very 

 minute ; the pectoral fins large : the branchial apertures on 

 the sides of the neck elongated vertically, five in number, the 

 first rather the largest, the last the smallest ; the fourth aper- 

 ture over the anterior edge of the pectoral fin : the ventral 

 fins united almost to the posterior extremity in the males, 

 less completely united in females ; the elongated anal aper- 

 ture in the middle between them : the outer posterior mar- 

 gins, in both sexes, are as oblique as those of the front : the 

 right-hand figure of the vignette at the end shows the lozenge- 

 shape of the fins when seen from below. The first dorsal fin 

 is over the space between the ventral and anal fins, and occu- 



