AULOPORID^. 221 



marised as follows: i. The colonies oi Aulopora are parasi- 

 tic, the whole of their lower surface bein^ attached to foreign 

 bodies ; whereas the similar-looking basal reticulation of Sy- 

 ringopora was clearly attached only at one or two limited 

 points, the greater part of its under surface being free. 2. 

 The curved and reclined corallites of Aulopora are free only at 

 their terminations, and they do not give origin to erect branches; 

 whereas the basal network of Syringopora throws up numerous 

 erect corallites from its upper surface, and it has not been shown 

 that the network has any existence apart from the erect tubes 

 to which it gives origin. 3. The connecting - tubes of Sy- 

 ringopora are not known to be represented by any correspond- 

 ing structures in Atilopora. 4. The tabulee of Atdopora are 

 simply curved, or, if infundibuliform, do not appear to give rise 

 to any structure comparable with the axial tube of Syringopora. 

 5. Species of Syringopora abound in formations where the 

 genus Aulopora is hardly or not at all represented, while 

 colonies of the latter are common in deposits in which 

 Syringoporce are nearly or quite unknown. 



For the above reasons, I am at present unable to accept the 

 union of Aulopora with Syringopora, as advocated by some high 

 authorities. At the same time, there are one or two species 

 now referred to Syjdngopora (such as 5". serpens, Linn., of the 

 Upper Silurian) which have marked " Auloporoid " characters, 

 and which may prove on minute examination to be really 

 referable to the Auloporidcs. 



To Ro77iingeria, Nich. i = Quenstedtia, Rom.), the present 

 genus bears considerable external resemblance ; and if Rom- 

 inger is right in regarding Aulopora cornuta, Bill., as only the 

 young of Romingeria, this resemblance would seem to be based 

 upon real affinity. As far as our present knowledge goes, how- 

 ever, we are constrained to separate Romingeria from the 

 AuloporidcF, as it possesses " mural pores " in parts, while it 

 further differs from Atdopora proper in having an erect 

 corallum. 



As regards its geological range, the genus Aulopora seems 



