The nostril in the Perch has two external openings, surrounded by several orifices, through which issues a mucous secretion for the defence of the skin against the action of the water. "The distribution of the mucous orifices over the head," remarks Mr. Yarrell, "is one of those beautiful and advantageous provisions of Nature which are so often to be observed and admired. Whether the fish inhabits the stream or the lake, the current of the water in the one case, or progression through it in the other, carries this defensive secretion backwards, and spreads it over the whole surface of the body. In fishes with small scales, this defensive secretion is in proportion more abundant; and in those species which have the body elongated, as the Eels, the mucous orifices may be observed along the whole length of the lateral line."[1]
Family II. Sphyrænadæ.
(Sea-Pikes).
The fishes of this Family were placed by Linnæus among the Pikes, which they resemble in their lengthened form, in their strong and pointed teeth, and in the projection of their lower jaw. They are now, however, widely removed from that genus. Cuvier arranged them in the great Family of the Perches, with which they have many points in common; but the Prince of Canino forms them into a distinct Family.
They have the ventral fins placed considerably behind the pectorals, and the bones of the pelvis
- ↑ Brit. Fishes, i. 4.
