404 COELENTERATA ANTHOZOA chap. 



the pores become largely filled up during the later growth of the 

 coral. 



There are several genera of colonial Fungiidae of less frequent 

 occurrence, such as Halomitra, Hei-petolitlia, and Gryptabacia. 



Fam. 7. Cycloseridae. — These are solitary or colonial 

 Fungacea with an imperforate theca. Bathyactis occurs at 

 great depths. Diaseris, shallow water on coral reefs. 



Fam. 8. Plesioporitidae. — The septa in this family are 

 trabeculate and perforate, resembling in this respect the septa 

 of Poritidae. Leptophyllia, Microsolena, extinct. 



Fam. 9. Eupsammiidae. — This family of perforate corals is 

 usually placed with the Madreporidae and Poritidae in the old 

 group Perforata. The researches of Fowler and G-ardiner have 

 shown that the arrangement of the mesenteries is that of the 

 Cyclocnemaria, and the presence of synapticula connecting the 

 septa suggests affinities with the Fungacea. The synapticula 

 of the Eupsammiidae, however, are peculiar in being arranged, 

 not in a vertical series, but alternately with one another or 

 quite irregularly in position. The members of this family are 

 solitary or colonial in habit. 



Stephanopliyllia is a flattened disc-shaped coral, with per- 

 forate and dentate septa, found in the Pacific Ocean and as a 

 fossil in various strata since Cretaceous times. 



In Zeptopenus, from depths of about 1500 fathoms, the per- 

 forations are much larger than in the last-named genus, and the 

 skeleton is reduced to a system of slender trabeculae. 



Bhodopsammia has a conical shape, and gives rise by gemma- 

 tion to a number of young zooids, which remain attached for 

 some time to the parent form before becoming free. 



Among the colonial genera are Dendrophyllia, Coenopsammia, 

 and the well-known Mediterranean genus Astroides. 



Order IV. Zoanthidea. 



This order of Zoantharia consists of a number of solitary or 

 colonial Anemones that do not form a skeleton of horn or 

 carbonate of lime, and are distinguished from the Actiniaria by 

 the peculiar arrangement of their mesenteries. 



Fam. 1. Zoanthidae.' — Sphenopus is a solitary coral and 

 terminates aborally in a small sucker-like base, by which it may 



