GEN. SCFLLIUM. 299 



while the young are maturing. The foetus is coiled 

 up in the centre, and is nourished by an umbilical 

 bag of a pyriform shape, filled by a yellowish vitel- 

 line matter. When the young is mature, it makes 

 its escape by an opening at the square end, at the 

 place next the head. These eggs are often found 

 on the sea-shore after they have lost their tenant, 

 and are known by the names of sea-purses, sailor's 

 purses, mermaid's purses, &c. 



The males are smaller than the females, and are 

 provided with two peculiar organs, placed near the 

 inner edge of the ventral fins. The name Claspers 

 usually given to these, sufficiently indicates the 

 opinion entertained by naturalists as to their use. 



The flesh of Sharks is frequently eaten, but it 

 has little to recommend it ; the Sicilians are said to 

 consider the young as very palatable. No Shark 

 is possessed of scales ; the skin is rough with small 

 siliceous-like particles, which protect and defend it. 

 When dried, the skin forms an article of commerce, 

 and is used for polishing wood ; also as a cover- 

 ing for boxes, watch-cases, &c. under the name of 

 shagreen. The liver of some of the larger species 

 affords a large quantity of oil. 



Gen. CV. SCYLLIUM. The presence of an anal 

 and two dorsal fins, the first dorsal never placed 

 in advance of the ventrals ; and the existence of 

 temporal orifices, are the chief distinctions of this 

 group. The branchial openings are five in number, 

 and placed partly above the pectorals ; the nostrils 

 near tl>e mouth. The teeth are small, sharp, and 



