320 THE SEA SHORE 



also known as the Nurse Dog and the Bull Huss ; and the Lesser 

 Spotted Dogfish (S. catulus), called also the Huss and the Kough 

 Hound. The egg capsules of both these are occasionally washed on 

 the beach, and those of the latter species may be known by the 

 yellowish colour and the long tendrils by which they are anchored 

 to sea weeds. 



In addition to these we may briefly refer to two of the Blue 

 Sharks (family Carchariidce) that frequent our shores, distinguished 

 by their long and prominent muzzle, and the crescent -shaped 

 mouth. They may be regarded as higher in the scale of fish life, 

 as compared with the sharks and rays previously named, because 

 the vertebrae are more or less hardened by the deposit of calcareous 

 matter, and, therefore, make a nearer approach to the character of 

 true bone. The species referred to are the Common Blue Shark 

 (Carcharius glaucus), and the Smooth Hound (Mustelus Icevis). 

 The former often exceeds twelve feet in length, and is commonly 



Fia. 231. THE SMOOTH HOUND 



seen off our south and west coasts during the summer months. It 

 is a nocturnal marauder, and is said to sleep at the surface by day 

 with its tail exposed above the water. The Smooth Hound is a 

 bottom feeder, subsisting on molluscs and crustaceans, the shells of 

 which are easily crushed by its flat and blunt teeth. It is a small 

 shark, measuring only three or four feet in length, and brings forth 

 its young alive. 



The next division (Teleostomi) contains all the bony fishes, 

 which may be distinguished generally from the cartilaginous group 

 by the following features : The skeleton is more or less hardened 

 by the deposit of calcareous matter, and the tail is generally not 

 of the heterocercal type. The paired fins are fan-like, and the 

 pectoral girdle is attached to the hinder part of the skull. These 

 fishes generally have an air-bladder, and the gills lie close together 

 in a cavity covered by an operculum. The eggs, too, are generally 

 very small and numerous, and massed together. 



