SUB-CLASS II. SIPHONOPHORA (Gr. siphon and phero, I carry. All of this sub-class are free, and composite. They are very beautiful, delicate organisms, chiefly inhabiting the surface of tropical seas. There are two orders: Order I. Calyeophoridtv (Gr. kalyx, a cup, and phero, I carry). The bodies of the polypites in this order are distinctly divided into three portions, called proximal, median. and distal. The proximal ends are provided with protecting plates called bracts. The calycophoridte have swimming bells by which they propel themselves through the water. Huxley divides this order into four families: diphydm, splimronectidte, prayidge, and hippopodidve.
Order II. Phygophoritice (Gr. physa, an air-bladder). The polypites of this order resemble those of the precediqg in (min, but the tenacles are more complicated, and are sometimes several inches in length. They also have peculiar bodies, called feelers, or pulpi, which resemble immature polypites, The reproductive organs are developed upon special processes, called gonoblastidia, which sometimes remain permanently attached, or are thrown off as free-swimming The genus physalia is the Portuguese, man-of-war. See PIIYSALIA, The order is divided into several families by 'Huxley.
Son-CLASS III. HUCERNARIDA. (Lat. bueerna, a lamp). These are the sea-blubbers, sea-jellies, hidden-eyed meduste. Divided into three orders: Order I. Lueernaricke. This order comprises those lucernarida which have only a single polvpite, and are fixed, but only for a time. Reproductive elements developed
kin the walls of the umbrella, without the intervention of free zoilids.
Order IL Petagidte (Gr. pelagos, sea). These animals, like the preceding, have only a single polypite, but have an umbrella with marginal tentacles in which are developed the reproductive elements.
Order HI Ilhizostomide (root-mouthed lucernaridee). In this order the reproductive elements are developed in free zooids, produced by fission from attached lucernaroids. The umbrella of generative is without marg.oal tentacles, and the polypites are numerous, forming with the ge,netalia a dendriform mass depending from the um orella (Greene). See 11111ZOSTOMIll1E and ACALEP11.11 Sun-cLAss IV. GBAPT01.1T1ME (Gr. grapiw, I write). Rhabdophora of Allman. The members of this sub-class are all extinct, but their nearest living allies are the ser tularians. Their structure is not easily made out. They arc generally found in pyrit ous impressions, having a silvery luster. in the Silurian formations, and are character istic fossils. See GBAPTOLITES and SERTULARIA.
V. HYDROCORALLINiE. This sub-class has been formed by Mr. Moseley for the reception of two groups of marine animals which produce a regular skeleton of carbonate of lime, often of large size, and which have been hitherto generally referred to the corals. See MILLEPORE and STYLASTERIDA-.