The most interesting type is the _Synanceia_ termed by the Creoles of Réunion _Crapaud de mer_, and by those of Mauritius _Laffe_. In Java it is called _Ikan-Satan_ (Devil-fish), and in Tahiti _Nohu_. It is distributed throughout almost all the warmer regions of the Indian and Pacific Oceans, and is found in Cochin-China and New Caledonia. It is never taken in the open sea, but only among the fringing reefs, where it lives constantly concealed in holes or buried in the sand. It does not come out except to make a sudden dart at prey passing within its reach. When irritated it does not eject venom; for the latter to be expelled one has either to press hard upon the poison-sacs, after pushing back with the fingers the membranes covering the dorsal defensive armature, or the naked foot must be placed on the back of the fish. The wound is very painful, and is accompanied by a series of alarming symptoms, which sometimes terminate fatally: fishermen are consequently much afraid of it. There are a large number of species of this fish, peculiar to different regions. _Synanceia brachio_ (fig. 101), the largest specimens of which attain the length of 45 cm., is the most common form in the Tropical Pacific. [Illustration: FIG. 101.--_Synanceia brachio_, var. _verrucosa_. (After Savtschenko.)] The spiny rays of the dorsal fin of _Synanceia_ are sharp-pointed, stout in the middle, and provided on each side with a small canal hollowed out in the thickness of the spine. Towards the middle of the latter there is attached a little double sac, or kind of closed pouch, which, on being compressed, allows the venom to escape in a thin jet which flows into the grooves of the spine. The expulsion of the venom is therefore not a voluntary act on the part of the fish; in order that it shall take place, pressure must be applied to the sacs in which it is contained. This venom, when extracted from the glands, is limpid, bluish, and slightly acid. When introduced into the tissues, it produces very acute local pain, which extends throughout the affected limb. The pain is excruciating, and sufferers have been observed to become actually delirious, striking and biting those around them, throwing themselves from side to side, and beseeching that the limb should be cut off; some of them have amputated the injured part themselves. This condition is accompanied by considerable anxiety, and by attacks of leipothymia and sometimes of syncope. In some cases syncope has been followed by death; in others serious phlegmons, complicated by septicæmia, supervene. The inoculated spot becomes bluish, and then sphacelates over a larger or smaller area. These gangrenous wounds heal very slowly, more especially since they are usually produced on the sole of the foot (Bottard). A single drop of the venom is sufficient to kill frogs in about three hours. [Illustration: FIG. 102.--_Cottus scorpius_ (Sea Scorpion). (After Savtschenko.)]