26 Proceedings of the Royal Irish Academy. 



If a preparation of spicules be made in the manner described, there 

 should be no difficulty in at once deciding whether or not the type described 

 and figured, as a "club," is present or not. (See figs. 4, 14, 23, and 26.) 

 On the other hand, figs. 114, 115, 116, and 118 give a good idea of the " long- 

 spindle type " and its proportion to the small double-club. Any of the figures 

 given of the various species of Scirpearia — e.g. figs. 27, 31, or 65 — will at 

 once mark these off as quite distinct from the other two types. 



VI. — Possible Affinities of the Gokgonellidae. 



In the "Challenger" Report on the Aleyonaria (vol. xxxi.), Wright and 

 Studer divide the (lorgonacea into two large sections : — 



I. Scleraxouia, and 

 II. Holaxonia. 



In the Scleraxouia they recognize the Sclerogorgidae as a distinct fam'ily, 

 with the following characters : — " In the representatives of this family a 

 distinct axis is formed of a tissue consisting of numerous closely intercalated 

 elongated spicules, with dense horny shields. The axis is surrounded by 

 longitudinal canals, into which there oj)eii the reticulated coenenchymatous 

 canals uniting the polyps." 



In the Holaxonia there occurs the family Gorgonellidae, in which " the 

 axis is lamellar and calcareous, but retains its shape after the extraction of 

 the calcareous matter." 



The nature of the " calcareous matter " is, however, not specified, so that 

 it is very difficult to interpret exactly what may have been the opinion of 

 these authors. 



In " A Treatise on Zoology," part ii., Bourne divided the Aleyonaria 

 into five large orders as follows : — 



(1) Stolonifera. 



(2) Alcyonacea. 



(3) Pseudaxonia. 



(4) Axifera. 



(5) Stelechotokea. 



The Stolonifera, Alcyonacea, and Stelechotokea are sufliciently distinct, 

 and most certainly have no connexion with the Gorgonellidae, so that any 

 further reference to them would be superfluous. 



The Pseudaxonia have been described as " Synalcyonadea forming upright, 

 branched colonies. The zooid cavities short ; the zooids embeilded in a 

 coenenchyma containing ramifying solenia and numerous spicules. The 



