A very singular little group of fishes, for example, is that known to the naturalist by the name Lophobranchii; this term meaning literally “tuft-gilled.” Included in this division are two curious families, of one of which the sea-horses or Hippocampi are the representatives; while to the other family belong their allies, the pipe-fishes. No more interesting forms than these two groups can well be selected from the great class of which they are little-known members. And the interest with which they are regarded by zoologists extends beyond the mere investigation of their outside form or appearance; since they present, in many points of their economy and habits, very marked deviations from what one may call the ordinary course of fish-life. Imagine a little body from four to six inches in length, topped by a head which in outline exactly resembles that of a horse, and which tapers off below, or rather behind, into a lithe, flexible, and pointed tail, and we may form a rough idea of the general appearance of one of the sea-horses. This little body we shall find to be covered with ganoid plates or scales of hard horny or bony material, exhibiting ridges and angles all over its surface. Two large brilliant eyes, each of which may be moved independently of the other, add to the curious appearance of the head; while to the body itself may be attached long streamers of sea-weed, serving to conceal the little beings as they nestle amid their marine bowers, each looking like some veritable creation of heraldic or mythological kind. The flexible tail which terminates the body has the important office of mooring or attaching the fishes to any fixed object. As we see them in the aquarium, they are generally poised, as it were, on the tail; the latter being coiled around a bit of sea-weed, while the erect body and head look warily through the waters of their miniature sea. When they detach themselves, they swim about in the erect position by means of the two pectoral or breast fins, which being placed close to the sides of the neck, project like veritable ears, and assist in rendering the equine appearance of the head of still more realistic nature. These fins move with a quick twittering motion, and propel their possessor swiftly through the water; while the back-fin, placed toward the hinder extremity of the body, also assists them in swimming.