FAM. TRACHYNEMIDAE.—In this family there are eight radial canals, and the statorhabs are sunk into a marginal vesicle. _Trachynema_, characterised by its very long manubrium, is a not uncommon Medusa of the Mediterranean and the eastern Atlantic Ocean. Many of the species are small, but _T. funerarium_ has sometimes a disc two inches in diameter. _Homoconema_ and _Pentachogon_ have numerous very short tentacles. FAM. PECTYLLIDAE.—This family contains a few deep-sea species with characters similar to those of the preceding family, but the tentacles are provided with terminal suckers. _Pectyllis_ is found in the Atlantic Ocean at depths of over 1000 fathoms. FAM. AGLAURIDAE.—The radial canals are eight in number and the statorhabs are usually free. In the manubrium there is a rod-like projection of the mesogloea from the aboral wall of the gastric cavity, covered by a thin epithelium of endoderm, which occupies a considerable portion of the lumen of the manubrium. This organ may be called the tongue. _Aglaura_ has an octagonal umbrella, and a manubrium which does not project beyond the velum. It occurs in the Atlantic Ocean and Mediterranean Sea. {295}FAM. GERYONIIDAE.—In this family there are four or six radial canals, the statorhabs are sunk in the mesogloea, and a tongue is present in the manubrium. _Liriope_ (Fig. 137) is sometimes as much as three inches in diameter. It has a very long manubrium, and the tongue sometimes projects beyond the mouth. There are four very long radial tentacles. It is found in the Atlantic Ocean, the Mediterranean Sea, and the Pacific and Indian Oceans. _Geryonia_ has a wider geographical distribution than _Liriope_, and is sometimes four inches in diameter. It differs from _Liriope_ in having six, or a multiple of six, radial canals. _Carmarina_ of the Mediterranean and other seas becomes larger even than _Geryonia_, from which it differs in the arrangement of the centripetal canals. _Liriantha appendiculata_ sometimes occurs on the south coast of England during September, October, or at other times. ORDER VIII. NARCOMEDUSAE.