TUBULOSA. 



205 



shaped, without tabulae, and having the septa indicated by 

 mere striae on the wall (fig. 97, B). The family is entirely 

 Palaeozoic, and its systematic position is wholly doubtful. 

 Save for the alleged absence of tabulae, its nearest ally ap- 

 pears to be Syringopora. 



In Aulopora, a genus which ranges from the Silurian to 

 the Carboniferous, the corallum (fig. 97, A) is compound, and 

 grows parasitically upon foreign bodies. The corallites are 



Fig. 97. A, Portion of Aulopora tubceformis, of the natural size ; and B, Portion of the same, 

 enlarged (after Goldfuss). Devonian, c, Cladochonus (Pyrgia) Michelini, of the natural 

 size, and enlarged (after Milne-Edwards and Haime). Carboniferous. 



tubular or pyriform, produced by lateral gemmation, and 

 furnished with a strong imperforate wall. In the Carbon- 

 iferous genus Cladochonus (Pyrgia), on the other hand, the 

 corallum is typically simple, and resembles a free corallite of 

 Aulopora. 



