STYLASTERID^. 33 



Eupsammid!:© ; but besides the porous ca^nenchyma, there is another 

 character connecting the two fainiUes, though in a somewhat remote 

 degree : it is the tendency of the septa to imite 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- 

 mida^, is carried to excess in the »Stylasterida3, 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 Turbinarinfe M.-Edw. & H. has also consider- 

 able affinities with the Stylasterida^, having like them all the septa 

 alike. 



In Stylasterida? the calicle is invaded by the cajnenchj-ma, and in 

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

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

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

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

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

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

 True dissejTiments do not appear to exist. 



I have, unfortunately, never succeeded in obtaining a satisfactory 

 view of the living polyp of an}- of the corals of this family, nor am 

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

 of the classification may l)e much modified. The so-called ampulla?, 

 peculiar to this family, were found iu the fresh polyp to be filled with 

 a yellow mass resembling the yolk of an egg. 



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

 laster, Distichopora, Cryptohelia (^ Eudohelia ? ) Lepidopora, n. g., and 

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

 identical with Madracis, and which belongs to an entirely different 

 fiiniily. 



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

 differing only by their mode of growth. Steuohelia 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 

 cajnenchyma. 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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