BUTTERFLY-GURNARD.
The head of all gurnards is encased in an armour of bony plates.
The Bull-heads and Gurnards, constituting the next family, are characterised by the spiny armature of the head and the great size of the breast-fins. The former are represented in British waters by four species, one of which, the Miller's-thumb, inhabits fresh-water. The marine species include the Sea-scorpion and Father-lasher.
The Bull-heads on the Indian and Australian coasts are represented by the closely allied Flat-heads, or Crocodile-fishes, in which the head, as its name implies, is much depressed, and fully armed with spines, which are highly poisonous, and cause a violent irritation. These fishes live in shallow water, lying on the bottom, with which their colours harmonise so completely that they are practically invisible. The very large ventral fins—those seen in the photograph immediately behind the breast-fins—are of great use in locomotion.
Photo by Reinhold Thiele & Co.] [Chancery Lane, W.C.
REEL-GURNARD.
The curious finger-like processes are used as organs of touch as well as locomotion.
The Gurnards are well-known fishes, common on the coasts of Britain, and extending from tropical to arctic seas. Their curiously shaped heads give them a very quaint appearance. One of the most remarkable peculiarities of these fishes is the separate condition of some of the rays of the breast-fins, which form finger-like organs, used to feel the ground and rake over loose stones, to discover small shrimps and other animals hidden underneath. Furthermore, the gurnards are peculiar in that they are enabled to communicate one with another by means of sounds produced by the expulsion of air from one compartment of the air-bladder to another. The females are much more common than the males, and also slightly larger. The young are remarkable for the enormous size of the breast-fins, though even in the adult these are unusually large.
