384 SPINY-PINNED GROUP. 



THE FLYING GURNARDS AND THEIR ALLIES, Family DACTYLOPTERID^. 



Another family of the present section is typified by the so-called flying 

 gurnards, and is easily recognised by the investiture of the body in an armour of 

 bony keeled plates or scales. In form the body is elongate and subcyclindrical ; 

 the teeth are weak ; and there is a bony stay connecting the preopercular with 

 the infraorbital ring. These fishes are all marine, some being pelagic, and they 

 are found in all seas, from the Arctic Ocean to the Equator, as well as in the 

 Southern Hemisphere. They are represented by an extinct genus (Petalapteryx) 

 in the Italian middle Eocene 



The curious-looking fish (Agonus cataphractus), figured in the 



accompanying illustration, is the British representative of a genus 



of small-sized fishes inhabiting the northern temperate seas and extending into 



ARMED BULL-HEAD ( nat. size), 



the Arctic Ocean. They are characterised by the angulation of the head and body, 

 which are invested in bony plates ; the small size of the teeth in the jaws ; the 

 two dorsal fins ; and the absence of appendages to the pectorals. Of the armed 

 bull-head, as the British species is popularly termed, Yarrell writes that it is not 

 " uncommon along the line of our southern coast, where it is well known ; and the 

 young of small size are frequently taken by the shrimpers in most of the sandy 

 bays at the mouth of the Thames and of other rivers ; on the eastern coast it is 

 very plentiful It seldom exceeds 6 inches in length ; its food is aquatic insects 

 and crustaceans ; it spawns in May, depositing the ova among stones, and its flesh 

 is said to be firm and good." Somewhat curiously, an outlying representative of 

 the genus occurs on the Chilian coast. 



