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CHAPTER IX. 



AULOPORID^:. 



THIS family can only be treated very briefly, partly because the 

 materials at present in my possession are insufficient for its 

 complete elucidation, partly because these materials have not 

 yet been fully examined, and partly because the small size and 

 parasitic habit of the type-forms give rise to special difficulties 

 in the way of their satisfactory examination by means of thin 

 sections. The genus Aulopora, Goldfuss, with its ally Clado- 

 cJionus, M'Coy (= Pyrgia, E. and H.), was originally referred 

 by Edwards and Haime to a special division of Zoantharia, to 

 which the name of Z. Tubulosa was given. This division was 

 stated to be characterised (Pol. Foss. des Terr. Pal., p. 310, 

 1851) by the fact that the corallites are pyriform and destitute 

 of " tabulae," and the septa are represented only by vertical 

 striae, while the walls of the thecae are wholly imperforate ; but 

 the undoubted presence of tabulae in typical forms of Aulopora 

 removes the only ground for the retention of the Tubulosa as 

 a distinct division of Zoantharia. The corallum in Aulopora 

 (fig. 31, D) has the form of a creeping, branched or reticulate, 

 system of tubes, attached by the whole of the lower surface 

 to the exterior of a shell, coral, or other foreign body. The 

 basal and prostrate stolons send up tubular or trumpet-shaped 

 corallites at longer or shorter intervals ; but though the ter- 

 minal portions of these are free, the length of the tubes is al- 

 ways very limited, and the reclined corallites never grow up 

 into a fasciculate mass. The walls of the corallites are quite 



