334 FISHES. 



the first opposite to the ventrals. Skin with scattered large 

 round tubercles. Nostrils midway between the mouth and the 

 end of the snout. Teeth equal in both jaws, very oblique, the 

 point being turned outwards ; several strong denticulations on 

 each side of the principal point. Spiracles small. 



The " Spinous Shark " is readily recognised by the short 

 bulky form of its body, short tail, and large spinous tubercles. 

 It is evidently a ground-shark, which probably lives at some 

 depth and but accidentally comes to the surface. More 

 frequently met with in the Mediterranean, it has been found 

 several times on the south coast of England, and near the 

 Cape of Good Hope. 



Euprotomicrus and Isistius are two other genera of this 

 family ; they are pelagic and but little known. 



Ninth Family — Ehinid^. 



No anal fin ; tivo dorsal fins. Spiracles present. Pectoral 

 fins large, with the hasal portion prolonged forwards, hut not 

 grown to the head. 



Ehina. — Head and body depressed, flat; mouth anterior. 

 Gill-openings rather wide, lateral, partly covered by the base of 

 the pectoral. Spiracles wide, behind the eyes. Teeth conical, 

 pointed, distant. Dorsal fins on the tail. 



The "Angel-fish," or "Monk-fish" {Eh. squatina), ap- 

 proaches the Eays as regards general form and habits. With- 

 in the temperate and tropical zones it is almost cosmopolitan, 

 being well known on the coasts of Europe, eastern North 

 America, California, Japan, South Australia, etc. ; it does not 

 seem to exceed a length of five feet ; it is viviparous, produc- 

 ing about twenty young at a birth. 



Extinct forms, closely allied to the "Angel-fish," are 

 found in the Oolite, and have been described as Thaumas. 

 The carboniferous genus, Orthacanthus, may have been allied 

 to this family, but it was armed with a spine immediately 

 behind the head. 



