The family ANTHOPTILIDAE contains the species _Anthoptilum grandiflorum_, which has a wide distribution in depths of 130 to 500 fathoms in the N. and S. Atlantic Ocean. It is perhaps the largest of all the Pennatulacea, specimens having been obtained from the Cape of Good Hope over 4 feet long with expanded autozooids, each more than half an inch in length. The family KOPHOBELEMNONIDAE contains a number of forms with remarkably large autozooids arranged in irregular rows on the two sides of the rachis. The siphonozooids are numerous and scattered, and their position is indicated by small papilliform calices on the coenenchym. The surface of these pens is usually rough, owing to the presence of numerous coarse projecting spicules. _Kophobelemnon_ occurs in the Mediterranean in deep water, off the coasts of Ireland and Scotland, and in other regions. The family UMBELLULIDAE contains some of the most remarkable and interesting examples of the deep-sea fauna. The peduncle is very long and the rachis stunted and expanded. The autozooids are of great size, non-retractile, and arranged in a cluster or rosette on the terminal rachis. There is a wide structural range between the species. Some species have numerous large spicules, others have none. In some species the siphonozooids have a single pinnate or digitate tentacle, in others the siphonozooids {363}are of the usual type. _Umbellula_ appears to be a somewhat rare but cosmopolitan genus in deep water, extending from the Arctic to the Antarctic region in water ranging from 200 to 2500 fathoms. The interesting genus _Chunella_ was discovered by the German "Valdivia" Expedition at a depth of about 420 fathoms off the coast of E. Africa, and subsequently by the Dutch "Siboga" Expedition at a depth of about 500 fathoms in the Malay Archipelago. According to Kükenthal,[391] this genus with another closely allied genus _Amphianthus_ should form a new section of Pennatulacea, the VERTICILLADEAE. _Chunella_ has a long and very delicate rachis and peduncle, and the former terminates in a single autozooid and has five or six whorls of three autozooids, situated at considerable distances from one another. Spicules are absent. The full description of this genus has not yet been published, but it is clear that it occupies a very isolated position in the order. [Illustration: FIG. 160.—_Renilla reniformis_, a small specimen (34 mm.), showing the dorsal side of the expanded rachis. _A_, autozooid; _H_, the mouth of the axial zooid; _s_, siphonozooid; _St_, the short stalk. (After Kölliker.)]