GREY MULLETS. 
399 
body being covered with strongly keeled and striated scales; and by the first 
dorsal fin being composed of a number of short spines, and continuing to the 
second. The elevated lower jaw has a convex upper border, bearing a single 
series of rather small compressed and triangular teeth. Of the habits of this 
scarce fish nothing definite seems to be known; although in the young state it 
is found in company with floating jelly-fish. At a later period of its existence 
it probably descends to a considerable depth during the day, and comes to the 
surface only at night. It grows to a foot and a half in length. 
From the two preceding families the grey mullets, which con¬ 
stitute the third family of the group under consideration, may be 
distinguished by the total absence of a lateral line, the presence of only four stiff 
spines in the first dorsal fin, and the limitation of the number of vertebrae in the 
skeleton to twenty-four. The more or less elongate and somewhat compressed 
body is covered with cycloid or slightly ctenoid scales of moderate size; the cleft 
Grey Mullets. 
common grey mullet nat. size). 
of the mouth is small or medium; the teeth are feeble or wanting; the lateral eye 
is of moderate size; and the gill-opening wide. In some species there may be 
a fatty lid to the eye. The grey mullets ( Miigil ■), of which there is a very large 
number of species, are distributed over all temperate and tropical coast-regions, 
frequenting brackish-water estuaries, and in some cases ascending rivers for 
considerable distances. Feeding chiefly upon the animals and organic matter 
found in sand and mud, these fishes have a special straining apparatus in the 
pharynx for the purpose of preventing objects of too large size from entering 
the stomach, or foreign substances getting into the gill-chamber. It will be 
unnecessary to describe the structure of this apparatus here; but it may be 
mentioned that after triturating a mouthful of sand or mud between the 
pharyngeal bones, in order to extract such nutriment as it may contain, the grey 
mullets reject the mineral part of it. Another peculiarity is to be found in the 
structure of the oesophagus and stomach, the former being lined with long thread¬ 
like papillae, while the latter has its second portion furnished with muscular walls 
like the odzzard of a bird, although it is not divided into two lateral halves. 
