4 



PEor. p. MAETiN Duncan's reyision of the 



communicate with those of their neighbours through the 

 wall or with the outside medium. 



The arrangement of the soft parts of both of these sec- 

 tions is not very different^ and it presents a very close resem- 

 blance in most instances. 



According to Milne-Edwards and Jules Haime the great 

 family Fungidse (Dana) is intermediate between the two sections 

 mentioned above, and it was classified with the Aporosa. Here 

 the difficulty of the classification of the great group begins, and 

 I make the family Fungidse into a section Eungida. 



Dana's beautiful illustrations * and Moseley's investigations t 

 show that the soft parts of the Eungid?e difi"er from those of the 

 Aporosa and Perforata; and many years since L. Agassiz stated 

 that a genus of the AstrjcidiB, according to Edwards and Haime, 

 and one of the Aporosa hod the soft structures of a Eungid and 

 part of the hard ones also. This genus Siclerastrcea has tentacles 

 unlike normal Astrseida) and endothecal dissepiments in addition 

 to synapticula, and in this last respect only does it link the 

 Aporosa and the Eungida proper together. Palseontology has 

 shown that the genus Tliamnastrcea and others must be linked with 

 Siderastrcda. Hence a group of old Aporosa is placed with the 

 section Eungida. Moreover, a genus of the recent Perforata, 

 Coscinaria, has been shown to have synapticula, and many fossil 

 forms require to be dissociated from the Perforata and placed 

 in a group amongst the Eungida. 



Hence the former family Eungid se of Edwards and Haime 

 becomes a section Eungida, and has associated wuth it two tran- 

 sitional families — one the Siderastr?ean group, or the family 

 Plesiofungida^, and the other the Cyclolites and Microsolena 

 group, the family Plesioporitidse. Zittel % and E. Pratz § have 

 paved the way largely for this suggested classification. 



Section Madreporaria Tubulosa^ M.-Ediv. Haime. 

 The third section of the Madreporaria, according to 

 Milne-Edwards and Jules Haime, is that of the Madrepo- 



* Dana, Zoophytes, Exploring Expedition, 1846. 



t Prof. H. N. Moseley, F.E.S., Eeport on the Corab, 'Challenger ' Expedition. 



\ Zittel, * Handbncli Palaontol.' 



§ E. Pratz, ' Palasontographica,' 1882. 



