Mr. J. E. Uuerden on the Genus Alicia. 215 



vesicles. Hence arose the necessity of examining if the 

 various species of Alicia, to which Cystiactis bears some 

 external resemblance, agreed with it or the typical Bunodidge. 

 The sphincter of A. cosfce is shown on PI. IX. fig. 1, from 

 which it will be seen that it is a somev/hat weakly developed, 

 but greatly elongated, diffuse endodermal muscle. A section 

 through a vesicle is shown in fig. 2, exhibiting a hollow 

 structure. Since our Australian form and A. costce agree in 

 such an important essential as the sphincter, and also in the 

 nature of the outgrowths on the column, it becomes necessary 

 that a new family should be established for their reception 

 and others closely allied to them, as they are obviously 

 different from any of those at present described. I propose 

 the family name Aliciidae, after the genus Alicia, with the 

 following characters : — 



Fam. Aliciidse. 



Hexactinse with a large flat contractile base. Tentacles 

 simple, cylindrical, and entacmaeous. Column with simple 

 or complex hollow processes or vesicles over the greater part 

 of its surface, arranged mostly in vertical rows. No cinclides. 

 Sphincter muscle endodermal and diffuse, variable in amount 

 of development. Perfect mesenteries few or numerous. No 

 acontia. 



The family, as thus defined, includes the genera Alicia 

 and Cystiactis, and possibly others, such as Bunodeopsis, &c. 



The relationships of the Actiniaria are still in a very un- 

 satisfactory condition, and will be so until a greater number 

 have been examined anatomically. It is therefore somewhat 

 premature to discuss the position of the Aliciidee. External 

 characters alone would place them near the Bunodidte ; but 

 they are now shown to be separated by such an important 

 character as that of the sphincter muscle. 



The genus Cystiactis will be more fully discussed in a 

 paper shortly to be published by the Royal Dublin Society. 



Genus Alicia. 



Tissues very delicate. Tentacles elongated, more or less 

 retractile. Column with the distal vesicles pedunculated 

 and much divided, the proximal vesicles simpler and more or 

 less sessile. Sphhicter muscle feebly developed. Mesenteries 

 not very numerous ; two pairs of directive mesenteries. 



Should A. mirahilis, Johns,, when histologically examined, 

 be found to differ fundamentally from the foregoing definition, 



15* 



