Eight species are known from the southern parts of the European seas, and one from the Moluccas; they do not appear to exceed a length of five feet. According to the observations of E. P. Wright, some of the species at least live at a considerable depth, perhaps at a greater depth than any of the other known Sharks. The Portuguese fishermen fish for them in 400 or 500 fathoms with a line of some 600 fathoms in length. The Sharks caught were specimens of _Centrophorus coelolepis_, from three to four feet long. “These sharks, as they were hauled into the boat, fell down into it like so many dead pigs; there was not the smallest motion of their bodies. There can be no reasonable doubt that they were inhabitants of the same great depth as _Hyalonema_” and that, in fact, they were killed by being dragged to the surface from the pressure of water under which they lived. The dermal productions of some of the species have a very peculiar form, being leaf-shaped, pedunculate, or ribbed, or provided with an impression. SPINAX.--Each dorsal fin with a spine. Teeth of the lower jaw with the point so much turned aside that the inner margin of the tooth forms the cutting edge. Upper teeth erect, each with a long-pointed cusp and one or two small ones on each side. Spiracles wide, superior, behind the eye. Three small species from the Atlantic and the southern extremity of America. _Centroscyllium_ is an allied genus from the coast of Greenland. SCYMNUS.--Two short dorsal fins without spine, the first at a considerable distance from the ventrals. Dermal productions uniformly small. Nostrils at the extremity of the snout. Upper teeth small, pointed; lower much larger, dilated, erect, triangular, not very numerous. Spiracles wide. A single species, _S. lichia_, is rather common in the Mediterranean and the neighbouring parts of the Atlantic. LÆMARGUS.--All the fins small; two dorsal fins, without spine, the first at a considerable distance from the ventrals. Skin uniformly covered with minute tubercles. Nostrils near the extremity of the snout. The upper teeth small, narrow, conical; the lower teeth numerous, in several series, the point so much turned aside that the inner margin forms a cutting, non-serrated edge. Jaws feeble. Spiracles of moderate width. [Illustration: Fig. 123.--Dentition of the Greenland Shark. Some teeth are represented of the natural size; those of the lower jaw in three series.]