24 Coelenterata. 



any connection with the ectodermal lining of the stomodseum but in the case 

 of the complete mesenteries such a continuity is early established while in the 

 incomplete mesenteries the separation is permanent. In Madr. buds arise 

 along the superficial wall of a simple external canal. The 6 pairs of proto- 

 cuemes are fully established before the tentacles appear and the septa are as 

 yet unrepresented. The relations of the mesenteries are as in adult polyps. 

 At the aboral extremity of all the larvae of Madreporaria nervous elements 

 are developed in the ectoderm to such an extent as to suggest that this region 

 forms a sensory organ. The endoderm varies considerably. In some cases 

 the interior of the larva is hollow but lined by a thick endoderm, in others 

 it is filled with a vacuolated tissue the middle part of which later breaks 

 down and the organic debris thus formed is extruded shortly after the forma- 

 tion of the mouth. An account is given of the gonads and of the details of 

 development of Ago/rida, Isophyllia, Favia, Manicina and Siderastrcea. The 

 author suggests a new classification of the Madreporaria based upon the 

 metacnemic sequence and on other polyp characters. The principal subdivisions 

 are - - I. Entocnemaria in which the mesenteries always arise in bilateral 

 pairs and beyond the protocnemic stage the increase takes place within one 

 or both of the directive entoccels. A. Perforata: the basal disc forms canal- 

 like outgrowths perforating the skeleton which in colonies connect the different 

 ccelentera (Madr., Por.]. II. Cyclocnemaria in which the mesenteries beyond 

 the protocnemic stage arise in isocnemic pairs within the primary exocoels and 

 the mesenteries of the adult are in two or more alternating cycles. B. Aporosa: 

 the basal disc is imperforate and the ccelentera of colonial polyps are in com- 

 munication only around the proximal termination of the column: 1. Oculinidse, 

 2. Astrseadse, a Gemrnantes with tentacles, mesenteries and septa in alternating 

 cycles and two pairs of directives in each polyp (Astrangia, Phyllangia, Clado- 

 cora, Orbicetta, Solenastrcea) ; p Fissiparantes in which, after fission is estab- 

 lished, the tentacles, mesenteries and septa are not in regular cycles and no 

 new directives arise (Fav-ia, Dichoccenia, Isopli., Manidna, ColpophyUia and 

 Mceandrina). C. Fungacea: the mesenteries and the basal wall lining the 

 interseptal loculi are perforated by skeletal bars; tentacles often small, simple 

 or dimorphic, widely separated (Sid., Agaricia}. The anatomy and histology 

 of the above named genera are fully described. 



Dbderlein refers to the causes of the great variability and numerous forms 

 of reef corals. He gives an account of the features used in discriminating 

 species of Fungia and of the characters of young specimens. For asexual 

 reproduction and the relationships and characters into which the genus is sub- 

 divided see Bericht f. 1901 Coel. p 11. The memoir includes an account of 

 the distribution, a key to the species and a description of 26 species and 

 35 varieties of which 10 are new. 



Gardiner ( 3 ) regards Flabellum rubrum, F. stokesi and F. (Blastotrochus) nutrix 

 as varieties of a single species. In the development of rubrum there are 

 at first 6 septa which fuse together in the centre of the corallum forming a 

 false columella, then 6 additional septa are formed which fuse by trabecula? 

 with the first cycle. The corallite at this stage is about 2-3 mm. along the 

 long axis of the calicle. Development now proceeds more slowly and further 

 septa only begin to fuse in the calicle when a length of 8-10 mm. is attained. 

 During this pause the larger mesenteries commence to receive their generative 

 organs, small testicular acini, which increase in number and in size, appear- 

 ing in the mesoglcea. When the calicle is about 13 mm. long no further 

 testicular elements are added to the primary mesenteries but in the meantime 





