26 PALEONTOLOGY 



two iii the chalk and greensands. These are mostly Astrceidce, 

 or related to Fangia. Three common forms in the oolites are 

 Montlivaltia (fig. 5, 9), Stylina (fig. 5, 10) and Thecosmilia (fig. 

 5, 11). The English cretaceous strata afford the Holocystis 

 (fig. 5, 8), which is the most recent coral with quadripartite 

 septa ; Troclwcyathus and Parasmilia (fig. 5, 6), resembling 

 the recent Gyathina ; and the little " Fungia" coromda (fig. 

 5, 3), described in two genera of distinct orders {Micrabada 

 and Stcplianophyllia) in the " Monographs of the Palseonto- 

 graphical Society." The lower chalk of France and Germany 

 contains many other corals, especially Gydolites (fig. 5, 5), 

 Pachygyra (fig. 5, 7), and Diplodenium (fig. 5, 2). The Aspir 

 discus (fig. 5, 4) was sent by Dr. Shaw from Algeria. 



The English eocene strata contain twenty-five corals, all 

 extinct, and belonging to fifteen genera. These include an 

 Astrcea (Litharcea Websteri), which grows on the water-worn 

 flint pebbles ; a Bcdanophyllia, similar to the existhig coral : 

 a Dendrophyttia, which is the oldest member of the genus ; an 

 Oculina ; and eight species of the genus Tv/rhinolia (fig. 5, 1). 

 The corals of the English pliocene are mostly Bryozoa ; only 

 four true corals have been found in the coralline crag belong- 

 ing to the genera Sphcnotrochus, Flabellum, Crypta/ngia, and 

 Bcdanophyllia, all reputed extinct, although the first is very 

 closely related to the living Sphenotrochus Macandr&m. 



The total number of fossil corals enumerated by M. 

 d'Orbigny in the "Prodrome de Paleontologie," aim units to 

 1 1 35, grouped under 216 genera. But notwithstanding all the 

 labour which has been bestowed on this branch of palaeonto- 

 logy by Goldfuss, Michelin, Lonsdale, and Milne Edwards, 

 species are continually discovered or brought home from 

 abroad which are altogether new, and cannot be placed in any 

 of the constituted genera. 



