ACTINOZOA. 



207 



9 1 



Sclerenchyma reticulate. The- 

 coe not distinct from the sur- 

 rounding coenenchyma. 

 Sclerenchyma simply porous 

 Thec?e distinct. . 

 ' Syniipticulse present. No dis' 

 sepiments. . 

 Synapticulae absent. 

 Dissepiments in general numer 

 ous. Ccenenehyma absent 

 or formed only by the deve 

 lopment of the costse or epl 

 theca. 

 Dissepiments few or absent, 

 'Ccenenehyma compact, abun 



dant. 

 ^No ccenenehyma. . 



Family ii. PoaiTiD.B. 

 Family 12. Madeepobid.e. 

 Family 13. Fungid.e. 



Family 14. Astb;eid.s:. 



Family 15. Oculinid^. 

 Family i6. TufiBiNOLrD.s:. 



In addition to those here defined, Milne Edwards 

 has distinguished four other families of Apoi^osa, 

 which inosculate, so to speak, between the primary 

 groups just mentioned. The first family. Das- 

 midai, includes but a single genus, closely related 

 to the Turhinoliclce, from which it differs in the 

 peculiar modifications of its septa. Each of these 

 is represented by three vertical laminae, united 

 only along their external margin. A second 

 family, Stylophoridce, appears as a transitional 

 group between the Oculinidce and Astrceidoe, As 

 in the former, there is a well-developed ccenen- 

 ehyma and few dissepiments ; but, on the other 

 hand, the surface of the ccenenehyma is echinu- 

 late, while it is smooth in the Oculinidce, and the 

 thecal of the coral lites do not, as in that family, 

 increase endogenously, so as almost to obliterate 

 the loculi. Another osculant family, Echino- 

 poridce, still more closelj resemhles the Astrceidce, 

 differing therefrom chiefly in the possession of a 

 foliaceous, basal ccenenehyma. But one genus 



