STYLASTER1DJ2. 33 



Eupsammida3 ; but besides the porous casnenchyma, there is another 

 character connecting the two famihes, though in a somewhat remote 

 degree : it is the tendency of the septa to unite by their inner edges 

 and enclose, in the interseptal chamber thus formed, the septa of a 

 higher order. This character, more or less developed in the Eupsam- 

 midse, is carried to excess in the Stylasteridae, where sometimes the 

 interseptal chambers are so far removed from the central part of the 

 calicle as to lose all apparent connection with it. 



The subfamily of Turbinaringe M.-Edw. & H. has also consider- 

 able affinities with the Stylasteridae, having like them all the septa 

 alike. 



In StylasteridiB the calicle is invaded by the casnenchj^ma, and in 

 a great measure obliterated as in the Oculinidas proper. This char- 

 acter was relied upon, together with the fancied solid caenenchyma, for 

 associating these forms ; in reality the filling up of the Stylasteridae is 

 of a different kind ; the interseptal chambers, always narrow, are 

 continued down and merge in the fine canals of the ctenenchyma, 

 whilst the central fossa is obliterated by the growth of the columella. 

 True dissepiments do not appear to exist. 



I have, unfortunately, never succeeded in oljtaining a satisfactory 

 view of the living polyp of any of the corals of this family, nor am 

 I aware that it has been observed by others. When it is, our views 

 of the classification may be much modified. The so-called ampullar, 

 peculiar to this fimily, were found in the fresh polyp to be filled with 

 a yellow mass resembling the yolk of an egg. 



The genera forming this family are the following : Allopora, Sty- 

 laster, Distichopora, Cryptohelia (= Endohelia ? ) Lepidopora, n. g., and 

 Errina. Professor Verrill has also included Axohelia, which I consider 

 identical with Madracis, and which belono-s to an entirely different 

 family. 



Of these genera, Allopora and Stylaster are very closely allied, 

 differing only by their mode of growth. Stenohelia Kent, a new genus 

 established to receive Allopora madeirensis Johnston, and Stylaster 

 complanatus Pourt., I believe very difficult to maintain, as the pas- 

 sage from the Stylasters with circular calicle to those with an oval 

 one is very gradual, as is also the other character derived from the 

 obliteration of one of the lips of the calicle by the intrusion of the 

 CJBuenchyma. Cyclopora Verrill has all the fundamental characters 

 of a true Stylaster (the columella is well developed) ; it leads the 

 way towards Distichopora by its interseptal chambers becoming more 

 separated from the fossa, and the latter assuming a more elongated 

 form ; still, the differences from Stylaster proper are scarcely sufficient 

 to warrant a new generic name. Lepidopora, a new genus, forms the 

 passage from Stylaster through Cryptohelia to Errina, which is the 



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