146 VERRILL, CLASSIFICATION 



SUBORDER I. STAURACEA (Madreporaria rugosa*). 



Coral simple, or compound by budding; chiefly epider- 

 mal and endothecal ; septa apparently in multiples of four, 

 sometimes wanting. TyP e embryonic, like a young Astrea 

 or Fungia. 



Families', Stauridce, Cyatliophyllidce, Cyathaxonidce, 

 Cystiphyllidcz. 



SUBORDER II. FUNGACEA. 



Polyps either simple or compound by marginal or disk 

 budding, rarely by fissiparity. Tentacles numerous, in 

 multiples of six, imperfectly developed, scattered on the 

 actinal surface, usually short and lobe-like. Upper part 

 of polyps scarcely exsert. Coral broad and low, growth 

 mostly centrifugal, tissue chiefly septal ; walls imperfectly 

 developed, often perforate, subordinate, usually forming 

 the basal attachment. 



Families, Cydolitidce, Lophoseridce, Fungidaz, Merulini- 

 dce. 



SUBORDER III. ASTREACEA. 



Polyps mostly compound, either by fissiparity or vari- 

 ous modes of budding. Tentacles usually well developed, 

 long, subcylindrical, limited in number, in multiples of six 



* This group is placed here with considerable hesitation and princi- 

 pally on account of the close resemblance in structure to the young 

 of the succeeding and higher groups, when they first begin to form 

 a coral, which then consists of a ring of epitheca or epidermal deposit 

 with a few, imperfect, rugose septa radiating from the centre. If the 

 number four be a constant feature of the arrangement of their septa, it is 

 possible that they may be entitled to rank as a separate order of Polyps. 

 To this opinion Prof. J. D. Dana inclines. Prof. Agassiz unites the 

 group with Hydroid Acalephs on account of their resemblance, in some 

 features, to the Tabulata. It seems to me, however, that the absence of 

 transverse plates in Cyathaxonida and Cysliphyttida and the perfection of 

 the vertical septa in Stauridce, Cyathaxonidte and some of the Cyathophyl- 

 lida, together with their general structure, shows them to be more closely 

 allied to the Fungacea and Astreacea, of which they may be considered 

 embryonic types, while at the same time the group is a synthetic one, 

 having analogies with nearly all the higher groups of Polyps and also in 

 some respects, with Hydroids. 



