THE ANATOMY OF THE MADREPORARIA. 25 



2. The septa and tentacles are both ectoccdic and entoccelic, the 

 number of septa not being necessarily a multiple of six. 



3. Three series of centres of calcification are recognisable in the 

 skeleton, of which one lies in the theca itself, and the other two at the 

 summits of the ectocoelic and entoccelic septa respectively. 



iv. Memoirs referring to the Genus : — 



Milne-Edwards and Haime, " Hist. Nat. des Corall.," iii., 116. 

 Studer, Steinkorallen auf der Eeise S. M. " Gazelle " gesammelt, 



Monatsb. Akad. Berlin, 1877, p. 631, pi. i., Fig. 8. 

 Moseley, "Challenger" Eep. Zool., h\, 178, pis. viii., ix. 



Seriatopora subulata (Figs. 9-13). 



For the material for the study of this coral and of Pocillopora I 

 again owe my thanks to Professor H. N. Moseley, who has already 

 investigated the general anatomy of both forms (10). As, however, 

 no structural details have yet been figured, and these somewhat 

 aberrant forms are of great interest, no apology is necessary for a 

 second account of them. The specimens of Seriatopora were obtained 

 by Mr. Gulliver from Zanzibar. 



I. Corallum. — The characteristic feature of the skeleton which 

 caused both Seriatopora and Pocillopora to be ranked in the now 

 abandoned group of Tabulata is the presence of tabulae, i.e., 

 successive floors of coral, by which the living polyp shuts off its 

 ccelenteron from the cavity it previously occupied, a condition the 

 opposite to that described above in Lophohelia prolifera. The 

 calyces are therefore nearly confined to the outermost part of the 

 colony, and are not continued deeply into it, as was the case in 

 Turbinaria. These shallow calyces project but slightly above the 

 ccenenchyme, and at a very short distance below the orifice are 

 divided into two halves by the fusion of the two larger septa. These 

 two septa, the axial and the abaxial, are the only two that are 

 developed to any extent, though traces of the other ten may be 

 recognised in many cases [cf. the condition of Madrepora Durvillei 

 (3)]. When all are present there are six entocoulic and six ectoccdic. 

 It is perhaps more accurate to speak of the calyx as divided into 



