146 MADKEPOKARIA. 



SUPPLEMENTARY GONIOPOR^. 



Prbfatory Note. 



Since Vol. IV. was published, interesting new specimens of this genus have been added 

 to the collection, while a few others, which had for various reasons been overlooked, have 

 come to light. An account of these will be in place in this Volume, which closes the 

 Poritidse. 



Some explanation may naturally be required of the fact that specimens could be over- 

 looked. With regard to many genera such a confession might argue very careless sorting, but 

 not with regard to this. The liability to confuse Porites with Goniopora was noted again and 

 again in Vol. IV. Indeed, the earlier writers had no settled criterion, and confused them 

 freely. The distinguishing characters which have been adopted in these three volumes of the 

 Catalogue had to be worked out in the course of their preparation. 



But it is not only with Porites that Gonioporce may be only too easily confused, but also 

 with certain forms of Astrseids. As related in the historical review of the genus given in 

 Vol. IV., Goniopora was at one time classed with the Astraeids. It is not, then, surprising that 

 .specimens, such as those figured, say PI. VIII., figs. 4 and 7a, may, in the preliminary sortings, 

 very easily find their way into other groups, from which they are only rescued when those 

 groups themselves are submitted to close examination. 



The designations given in this Supplement continue, where possible, the different series 

 begun in Vol. IV. This affords an illustration of the simple method of adding up, fact by 

 fact, our knowledge of the genus. 



The presence of fossil Gonioporce in Jamaica, now recorded in this Catalogue, is of more 

 than ordinary interest, because of the additional light they throw on the history of the genus. 

 No recent forms are known from any part of the West Indian or Atlantic area. Yet it was at 

 one time plentiful along the eastern shores of the Atlantic, as we may gather from its presence 

 in the Bracklesham beds of Hampshire (Eocene), its abundance in the Paris Eocene and 

 Mediterranean basins (Eocene and Miocene). The bearing of these facts upon the suggested 

 connection (in the Miocene) between the Mediterranean and the West Indian regions must be 

 left to geologists. The oldest European records of the genus occur in Austro-Hungary (Upper 

 Cretaceous), and in the Crimea (Lower Cretaceous). (See Table II. p. 168, Vol. IV.) 



