7. Anthozoa (incl. Hydrocorallia^. A. Zoantliaria. 15 



among them. Large and small specimens, those with acute and with obtuse apices, 

 without and with tabulae all belong to the same species. S. will probably be 

 ultimately reduced to a synonym of Zaphrentis, as Rominger has already shown 

 that the two genera are not clearly separable. 



Lacaze-Dllthiers( 1 ) discusses the new environments and associated structural 

 peculiarities of Caryophyllia clavus. This species is usually found at a depth of 

 200 metres but at Port-Vendres occurs in shallow water, the embryos having 

 been carried thither by currents. The individuals do not reproduce by fission or 

 budding, their occurrence in clusters is due to the superposition and fixation of 

 embryos upon older specimens. 



Pratt describes the anatomy of the rare imperforate Madrepore Neohelia porcel- 

 lanci. There are apertures in the peritheca surrounded by a special columnar epi- 

 thelium in which are numerous large nematocysts (with long spirally-barbed threads) 

 and large granular gland cells. Around this aperture beneath the epithelium there 

 is a ccenosarcal canal in connection with the network of canals in the neighbouring 

 tissues. The canals place all the polyps in communication, one of them opening 

 into each intermesenterial space of the polyps. The coenosarc is supported upon 

 a horny layer secreted by the animal. There are 5 primary, 5 secondary and 

 10 tertiary tentacles and mesenteries. Only the primary and secondary mesen- 

 teries reach the stomodaeum and they alone bear gonads and acontia. There are 2 

 pairs of directive mesenteries. There are no nematocysts in the mesenterial fila- 

 ments. N. resembles in several respects the Cretaceous genera Diblasus and Bary- 

 helia, but is more nearly related to the former than to the latter. 



Bernard^) describes the skeleton of Porites giving details of the structure of the 

 walls of the calicles, the 12 septa (2 are directives), the pali and the columella. 

 The enteric cavities of the colony are simply a network of fine canals. Each of 

 the 12 tentacles bears a battery of nematocysts at the tip and a row of smaller 

 batteries on the inner face; between these the ectoderm contains numerous gland 

 cells. Symbiotic algae are present in the superficial tissues, and the living part of 

 the coral is also inhabited by a ciliate lufusorian (resembling Spirostomum) and 

 by fungal hyphae. 



Duerden( 2 ) has investigated the development of mesenteries in sexually- 

 produced polyps of Manicina areolata, Favia ananas, Cladocora arbuscula and 

 Porites and has also examined the buds of (7., Solenastraea and Madrepora. The 

 first 6 pairs of mesenteries ("protocnemes") differ essentially in their mode of origin 

 and significance from the "metacnemes", and the same remark applies to the "pro- 

 tosepta" fand "metasepta". The 12 primary mesenteries arise in the larva in 

 bilateral pairs in a definite order which is probably the same throughout Madre- 

 poraria and Actiniaria; 2 pairs of directives are always present in Madreporaria. 

 The first 4 pairs of mesenteries are the earliest to unite with the stomodaeum 

 (Edwardsia-stage) and a long interval may elapse before the 5 th and 6 th pairs 

 become complete and the secondary mesenteries begin to be formed. The develop- 

 ment of the primary mesenteries in buds is in close agreement with their 

 development in sexually produced polyps. Most of the polyps of Mad. and P. 

 never pass beyond the stage in which the primary mesenteries only are developed. 



- In most coral polyps the addition of mesenteries beyond the primary 6 pairs 

 takes place in successive unilateral pairs, the corresponding pairs on each side are 

 mostly simultaneous in appearance and always exocoelic in position. The first cycle 

 of secondary mesenteries, consisting of 6 pairs, arises in successive pairs 

 from one aspect of the polyp (ventral) to the other (dorsal) ; the pairs afterwards 

 become equal in size. They usually remain free from the stomodaeum but in large 

 polyps may become connected in successive order. The second cycle consists of 



