72 CLASS II. 



nearly one-half of the numerous species is found in America. Of 

 swimming polyparies (Pennatulce) , many species are found in the 

 Mediterranean, the Indian Ocean and the North Sea, and the large 

 Umbellaria of Greenland, which attains a length of six feet, is 

 remarkable. Of the stony polyparies, the greater number occur in 

 the seas of hot countries, as ex. gr. Madrepora, especially Astrcea, 

 Caryophylla, Fungia, Mceandrina. Most of the species of the last 

 genus are found in the Indian Ocean and South Pacific. The Red 

 Sea also has very many species from the division of these stony 

 polyparies. More than one-fourth of the known species of this 

 class were found there by EHRENBERGK Notwithstanding the 

 proximity, it seems that the Red Sea, with the exception of some 

 species of Actinia, has no species in common with the Mediterranean. 

 Isis nobilis (Corallium rubrum) appears to occur in the Mediter- 

 ranean alone. 



Of many genera numerous fossil species are found, especially of 

 those whose species now live in hot regions. Thus the genus 

 Astrxa numbers more fossil than living species : and these petrified 

 remains belong principally to the Jura- and chalk-formations. Still 

 more numerous are the fossil species, as compared with those now 

 living, in the genus Turbinolia. A genus which appears to connect 

 Fungia and Turbinolia, Cyathophyllum of GOLDFUSS, has quite died 

 out, and occurs in transition limestone. In the same way fossil 

 species alone are found of the genera Ceriopora, Favositis, Pustu- 

 lopora, Heteropora, Catinipora and Aulopora. The fossil Polyparies 

 prove, like all other remains of an earlier vegetable and animal 

 world, that the surface of our earth had in earlier times a higher 

 mean temperature than it has now. 



