OP NEW SOUTH WALES. 7 



Acalephs, to which they are now referred. They arc soHd and 

 stony corals, as much so in fact as any of the reef-building class. 

 They generally have a smooth surface, and are always without 

 any prominent calices, there being only very minute rounded 

 punctures over the surface from which the animals show them- 

 selves. Some of the principal reefs on the Carribean Sea are 

 mainly composed of Millepore corals. The cells in the zoothome 

 are divided parallel to the surface by very thin plates or tables, as 

 in the PocilUporce and Favosites, and they were formerly classed 

 therefore with the other tabulate corals. The following was the 

 arrangement proposed by Messrs. Edwards and Haime. 



Madreporaria tabulata. 



Corallum essentially composed of a highly developed mural 

 system, and having the visceral chambers divided into a series of 

 stages by a complete diaphragm or transverse dissepiment. 

 Septa rudimentary, either uniting or at most represented by 

 processes extending more or less into the visceral chamber. There 

 are four families in this section. A. ccenenchyma abundant. 

 1. Cellules or tubulee foliaceous or massive Milleporidce. 2. 

 Seriatoporidcs : compact in arborescent tufts. B. Little or no 

 ccenenchyma, the walls uniting with one another. 1. Favositidce : 

 walls lamellar. 2. Thecida : wall thick and compact. 



1st Family Milleporidj). 



Corallum composed of an abundant tubular or cellular ccenen- 

 chyma, distinct from the walls of the corallites. Septa, few ; 

 dessepiments well developed and numerous. 



M. Agasiz has proved that these animals are not corals, 

 properly speaking, but an intermediate form of Acalephs 

 between the embryo and adult state of Medusas. The Millepores 

 afford, therefore, examples of coral-making by species of the 

 class Acalephs. The corals are solid and stony, with a smooth 

 surface without any prominent calices, there being only very 

 minute rounded punctures over the surface from which the 

 animals show themselves. They have no resemblance to true 



