CHONDROPTERYGII. 185 



. SHARKS. 



Scyllium,* the Dogfish. 



A lengthened body, thick fleshy tail, and moderate 

 sized pectorals assimilate the Sharks to ordinary 

 fishes in outward form; the gill apertures, five in 

 number, open in the side of the neck, and not on the 

 under surface ; and the eyes are in the sides of the 

 head. The spine is completely divided into vertebra. 

 In the Dogfishes, the head is short and blunt ; the 

 teeth are pointed, and have a small lobe on each side 

 of the base : two dorsals, both placed far back ; tail- 

 fin lengthened, not forked. Most of them are 

 handsomely spotted with black, as is well seen in our 

 rare species, the Large Spotted Dogfish (S. Catulus). 

 The young, when produced, are enclosed each in 

 a horny case, of a yellowish colour, and an oblong 

 four-sided form, the corners of which run off into 

 long, slender and twisted tendrils. As they are depo- 

 sited in shallow water, these tendrils, hanging to weeds, 

 enable them to maintain their situation in spite of 

 the waves. The rough skins of these fishes are used 

 by cabinet makers for smoothing wood. They are 

 voracious and formidable animals. 



* SxwXaw, skylao, to prey ; or fxvXa^ ski/lax, a whelp ; answering to 

 Catulus. 



