4 THE VOYAGE OF H.M.S. CHALLENGER. 



thus making it possible to learn much about the anatomy of fossils. It has always 

 seemed to me that too much importance is now attached to peristomial characters, and 

 there are several genera which clearly require modification, so that shortly revision of 

 groujjs may be made by competent observers, but I do not think important results will 

 be obtained by an attack along the whole line. 



The genus Membranipora is now one of the largest, and no doubt contains many 

 forms which should be removed, but it does not seem that Mr. Busk has been successful 

 in his attempt to dismember it, since Foveolaria elliptica and Foveolaria tubigera are 

 placed together in a new genus, and distinctive characters seem difficult to find for the 

 groups which Mr. Busk called Amphiblestrum, Foveolaria, and Bijlustra. Also 

 Alembranipora galeata, Busk, Membranipora cervicornis, Busk, and Membranipora 

 {Amphiblestrum) cristata, Busk, are evidently very closely allied, and show that any 

 classification placing them in different genera must' be artificial. 



In the paper already referred to, several points raised in Mr. Busk's Report were 

 considered, and others were dealt with in a paper On the Use of the Avicularian 

 Mandible,^ &c., where I showed that " the articular process at each end of the base " 

 of the mandible in the famdy Adeonese is not confined to that family, as supposed, 

 but also occurs in Membranipora, Cribrilina, Flustra, &c. The so-called " columella " 

 in the mandibles of certain Celleporse I also showed was not distinctive of one division 

 of Cellepora, or of those in the Southern hemisphere, but occurs in several European 

 ones, and to this columella muscles are attached. In the mandibles of one Cellepora, 

 called Cellepora celosia (in MSS.) by Busk, I find there are two columellse, and in some 

 species of Diachons there are also two. A slight correction as to the operculum of 

 Schizoporella circinata (MacGiUivray) was made when describing the fossil form.^ The 

 opercula and mandibles of a few more species are now figured, and these chitinous 

 appendages, which I was the first to use, are constantly of the greatest diagnostic 

 value. 



In the Journal of the Linnean Society, vol. xx. p. 275, I have dealt at some length 

 with Handera (Idmonea) Jissurata, and hope shortly to describe Cellepora columnaris 

 more fully from a fine New South Wales specimen, and also, in some journal or 

 periodical, to give a fresh figure of Supercytis tubigera, as the series on the left-hand 

 side are double, instead of single, and the ovicell is flattened on the front and surrounded 

 with zocecia.^ There are also some species not yet recognised, and questions not com- 

 pletely studied, which have to be dealt with in subsequent papers. 



Except where the contrary is indicated, it may be taken that I found the specific 

 determination made, and, I presume, in every case by Mr. Busk. 



' Journ. Micr. Soc., ser. 2, vol. v. p. 774. - Quart. Journ. Geol. Soc, voL xliii p. 64. pi. viii. f^. 41. 



' When describing the New Zealand fossil, Supercytis digitata, B. (Qiuirt. Journ. Gtol. Soc, vol. xliiL p. 345), I made 

 an unfortunate mistake in considering it had been found in Victoria, instead of South Australia. 



