Page:Natural History, Fishes.djvu/99

Rh rays, and with the membrane often coloured; there are three free rays before the base of each, covered with a fleshy skin, well supplied with nerves. The ventrals are also large, and situated immediately beneath the pectorals. The anal corresponds with the second dorsal. The caudal is slightly lunate, or hollowed at the extremity. Both of the jaws, and the front of the vomer, are furnished with minute, close-set teeth. The gill-opening is large, and the branchiostegous rays are seven.

The swimming-bladder in this genus is rather large, and presents considerable diversity of form. In general it is somewhat heart-shaped, more or less cleft in front, but in the Sapphirine Gurnard, presently to be described, it is triple, the principal sac giving off, on each side, an accessory sac, tapering off to a point behind, but united to, and opening into, the main chamber at the front part. The membranes of which this organ are composed are thick, dense, and leathery.

Notwithstanding this development of the air-vesicle, the Gurnards are ground-fishes. They chiefly haunt the vicinity of the bottom, where they feed on crabs, lobsters, and other crustacea; not, however, confining themselves to these, for they are very voracious.

The Grey Gurnard (Trigla gurnardus, .) seems to affect the surface more than the other species of the genus. On the Atlantic shores of Scotland and Ireland it is not uncommon to see immense shoals of this Crooner, (as it is called on the former coast,) rippling the smooth water as they cut the surface, so as to be readily shot with a fowling piece.