•328 DE. S. J. HICKSON — REVISION OF THE 



value of classifications that have been seriously put forward in easily accessible publi- 

 cations ; but not only is my group, the Stolonifera, passed over in silence, but the name 

 is actually employed for a division of the genus Clavularia, vpithout one word of 

 comment or apology. Anyone who is not well acquainted with the literature of the 

 group might quite easily infer, on reading the ' Challenger ' report, that the term 

 " Stolonifera " is used for the first time by these authors. It is quite in keeping with 

 such work as this that no attempt is made in the volume cited to discuss the value of 

 the genera of the family Cornulariidse (Clavulariidse), which have recently been proposed 

 without sufiicient reason or description ; that the peculiar mode of budding of Clavu- 

 laria viridis is not referred to ' ; and that, in a word, the whole group remains in the 

 same state of confusion that it was in before the publication of that colossal memoir. 



Classification of the Alcyonaria. 



The Order Alcyonaria may be conveniently divided into the following five Sub- 

 orders : — 



1. Protoalcyonaria . Haimeia, Hartea. 



„ c. f Fam. 1. Clavulariida. 



2. OTOLONIFERA < 



L ,, 2. Tubiporidte. 



/-Fam. 1. Alcyonida. 



3. Alcyonacea ^ „ 2. Helioporida. 



^. etc. etc. 



. „ C Section I. Scleraxonia. 



4. (jORGONACEA < 



C „ II. Holaxonia. 



5. Pennatulacea Yaxa. Pennatulidce. 



The principal points by which this classification difi'ers from those put forward in 

 recent times by other authors are the separation of the Protoalcyonaria and Stolonifera 

 from the rest of the Alcyonaria as separate suborders, and the grouping together into 

 one suborder the Tubiporidse and the Clavulariidse. 



The value of a system of classification rests upon the correctness of the conception 

 of the relative values of the characters presented by the animals that are being 

 classified. A good classification is not necessarily the one in which the different groups 

 contain an approximately equal number of families or genera. It is generally recog- 

 nized now, for example, that it is not reasonable to include Amphioxus in the Class 

 Pisces, but that it is reasonable and far more correct to place this remarkable form in 

 a group by itself, the Acrania, which is to be considered of equal value to the whole 



' To illustrate the importance of this point, I may be allowed to quote some remarks of the late Professor 

 Moseley (lo): — "The existence of transverse communicating canals in Olavularia, extending between the 

 vertical tubes at successive heights above the stolon-tubes, as in Syringopora, is apparently a new fact, and 

 one of great interest." 



