an obvious and well-marked character in the form of the head, which is enormously dilated, so that the eyes appear placed at the ends of long projections. (See figure of Zygæna laticeps, an Indian species, on page 15.) These fishes attain a large size, and are said to be ferocious and formidable; one is occasionally taken on our coasts.
2. Pristina. The Saw-fishes. These are Sharks with many characters of the Rays; distinguished by the snout being prolonged into a straight flat bony blade, along the edges of which are set pointed teeth, directed outwards. This well-armed sword is a formidable weapon, which it is said the ferocious Saw-fish frequently buries in the flesh of the Whale and other marine animals. The preceding engraving represents the singular forms of these two Sub-families.
3. Squalina. The True Sharks. These have the ordinary form, the nose being somewhat pointed, the body slightly swelling behind the head. There are two dorsals, which have no
spines before them; and there are no air-holes (spiracles) behind the eyes. To this group, which far exceeds any of the others in the num-
