498 Scientific Proceedings, Royal Dublin Society. 



thickest extremity wliicli branclilet bifurcates at a distance of 3 mm. 

 from its insertion (PL xix. fig. 4). Small branchlets bearing the 

 calyces spring from the sides of the main branch and branchlet 

 irregularly at intervals of 2 or 3 mm. On the faces of the main 

 branch and branchlet may be seen the small round prominences 

 — the female gonads {gon.) — each about f mm. in diameter. The 

 diameter of the thickest branch is not more than 2 mm. 



The description of the species given by Milne-Edwards and 

 Haime is — Polypier flabelliforme. Les rameaux greles, cylin- 

 droides, tous situes dans le meme plane vertical, assez serres, non 

 coalescents, d'un rose orange, a I'exception des dernieres ramifica- 

 tions qui sont blanches. Le tronc principal a sa surface lisse ; les 

 rameaux presentent des stries microscopiques, et sont tous converts 

 de tubercules echinules. Calyces tous places sur deux lignes 

 opposees et paralleles, alternant avec ceux de la rangee voisines, 

 a bords en general un peu saiUants. Douze a seize cloisons, assez 

 minces, bien debordantes dans les calyces terminaux, plusieurs 

 d'entre elles formees par un repli de la muraille. Les polypiers 

 que nous avons observes ont quelques centimetres de hauteur, les 

 plus gros rameaux n'ayant que 5 millimetres de diametre; largeur 

 des calyces f mm. Habite I'Australie. 



So far as the specimen at my disposal goes, it agrees with 

 this description. The colour is white, and I have no evidence of 

 the colour of the rest of the colony. The microscopic striations 

 may be seen, but they are probably obscured by the preservation 

 of the soft parts. The number of " cloisons," that is to say, the 

 partition walls between the dactylopores, varies from twelve to 

 sixteen, but notwithstanding this fact, I have not been able to 

 count more than twelve dactylozooids in any of my sections. 



The first reference to Stylaster occurs in Pallas' " Elenchus 

 Zoophytorum," where a coral is described under the name 

 Madrepora rosea, that must belong to this genus. Ellis described 

 three species, Madrepora rosea, M. piirpurascens, and M. erubescens, 

 and it is quite possible that all of these were Stylasters. 



The Ccenosteum. 



The ccenosteum is probably flabellate in form. All the 

 branchlets in the specimen spring in the same plane right and 

 left from the sides of the main branch. The branch is almost 



