34 Coelenterata. 



are quite free. A day or two later 6 exosepta begin to appear in some cases 

 simultaneously, in others having a dorso-ventral succession. [For further details 

 on septal sequence see Duerden (*) above p 31.] In the adult the 12 largest septa 

 extend to the middle of the calice and unite with the columella, the 6 primary 

 ones are not connected with any other (except by synapticula), but with the 

 6 secondary ones are united the members of the third order which never reach 

 the columella; the members of the 4th or outermost cycle fuse on each side 

 with a tertiary septum. The calcareous ring above mentioned is a marginal 

 continuation or upgrowth of the basal plate and is therefore an epitheca. No 

 epitheca could be observed in adult coralla and in these there is no thecal 

 formation distinct from that of the septa, but the fusion of the peripheral ends 

 of the septa is complete and continuous causing the entire lateral separation 

 of one calicinal cavity from another. The basal plate always remained very 

 thin in the young specimens observed. The columella (which is a "true" one) 

 is formed from 3 distinct sources, (1) separate basal upgrowths, (2) septal 

 spines, (3) a secondary deposit which fills up the interstices between (1) and 

 (2). Synapticula are formed by fusion across an interseptal loculus of two 

 opposite granulations on the faces of adjacent septa. They are formed as 

 lateral processes of the septa either by an extension of the septal trabeculse 

 or from a centre of calcification of their own. These are the so-called "false" 

 and "true" synapticula, but there is no morphological distinction: both kinds 

 appear in the same corallite and the formation of the one or the other depends 

 on the interval between the septa concerned. The finer structure of the 

 corallum is also described. The so-called "centre of calcification" of the septa 

 is really the organic axis around which the skeletal matter is deposited in a 

 radiating or fan-like manner and in an early stage is occupied by a mesogloea- 

 like matrix within which the calcareous fibro-crystals are deposited. The 

 author observed a few abnormal larvae bifid at the oral end. Polyps acciden- 

 tally divided into two survived and formed normal but smaller individuals. 



Gardiner f 1 ) describes Antillia 1 n. var., Cylicia 1, Tridacophyllia 1, Eu- 

 phyllia 2, Mycctophyllia 1, Mussa 1, Symphyllia 1, Codoria 6 (2 n.), Leptoria 1, 

 Hydnophora 4 (2 n.), Favia 10 (4 n.), Goniastrcea 4, Aphastrcea 1, Orbicella 8 

 (2 n.), Cyphastrcea 6 (2 n.), Echinopora 4 (2 n.), Galaxea 5, Stephanoccenia 1 n., 

 Acanihastraa 1, Prionastrcea 1 (1 n.), Merulina 2. He gives the colours of 

 the corals in life and adds notes on the vegetative, continuous and discontinuous 

 variations. For remarks on this memoir, especially on the nomenclature see 

 Vaughan and Gardiner( 2 ). 



Heicke finds that in Rhodaraa lagrencei the polyps are of the actinian type. 

 "Sensory buds", forming a taste-apparatus, are present on the tentacles. Male 

 and female sexual cells are present at the same time in the mesenteries of the 

 same polyp. The nutritive canals have an arrangement analogous to that of 

 the canals in the more highly differentiated Alcyonacea. The asexually repro- 

 duced young individuals develop very similarly to those which are formed from 

 fertilised eggs. Besides asexual reproduction by budding from basal outgrowths 

 of the colony, there also occurs, in rare cases, multiplication by partial division. 

 In Cceloria sinensis the radial arrangement of the mesenteries and the septa 

 has disappeared and directive mesenteries are absent. Correlated with the process 

 of unequal division is the fact that the number of mesenteries is not constant. 



Krempf recalls that Fowler (1886) described, in about a third of the indi- 

 viduals of a colony of Madrepora durvillei, a considerable hypertrophy of the 

 endodermic layer of the upper part of 6 mesenteries, traversed by a U-shaped 

 canal (with ectoderaic walls) opening into the pharynx by 2 orifices. These 



