ISO SALT-WATER FISHES 



much the same arrangement of transverse plates as in the red 

 kind. Like the red gurnard, too, it has rows of spines along 

 the base of the dorsal fins. The pectoral fins are blue, but are 

 not displayed to any extent like the larger pectorals of the tub. 

 It is a small gurnard, rare in our seas, and reaching us from 

 the south of Europe. The men on the Plymouth trawlers 

 know it as the " offing " gurnard, presumably alluding to its 

 preference for deeper water. 



Cataphracti 



The Armed Bullhead and Gurnard 



The two fishes that follow, both belonging to a second 

 family, are distinguished by several easily recognisable characters 

 from the true bullheads and gurnards, but otherwise appear 

 to have certain affinities with those groups. 



The Armed Bullhead {^Agonus cataphractus) has its head 

 and body protected by bony plates, giving the head more 

 particularly the appearance of a solid geometrical figure. It 

 has two dorsal fins, and beneath the head there are many small 

 growths like threads. In colour it is yellowish grey, with 

 black vertical bands down the sides. It is a small fish, 

 only 5 or 6 in. in length, and its home is in the sand, 

 where it preys on minute crustaceans. Its teeth are weak, but 

 the small forms on which it feeds are probably soft. Like 

 the true bullheads, it lacks the air-bladder, whereas the next 

 species, like the true gurnards, has that organ. The spawning 

 of the armed bullhead was studied comparatively recently, and, 

 although Cunningham omits all mention of it, Mcintosh 

 devotes several pages to an account of its early life-history. 

 Its eggs, which are of the demersal kind, are deposited among 

 weeds, and the larvae are well developed when they emerge. 

 They are more brightly coloured than the adult, and live for a 

 time near the surface of the water, finally taking to a life at 

 the bottom of the sea, like their parents. The capsule of the 



