2 C. M. Maplestone: 



sutisfiu-toiy L'liissiHc;itii)n of the species abovenuuied, and the 

 new ones described in \\\\ re])oit upon the " Miner " jjolyzoa.l 



After reniarkinti' lliat the structural features jn-esented by 

 the various species of this yroup are of such an exceptional 

 character that it will be necessary to remove them altogether 

 from the family Se]e)iarii(](ie, in which most of them have been 

 placed, and that they appear to possess characters which are 

 either unknown or rarely found in other species of Polyzoa, Mr. 

 Whitelegge states that the " method of growth (not habit or 

 form) or increase in size of the zoarium by the addition of new 

 zooecia is intercalary, taking place on the surface between the 

 cells already formed and not at the outer margin, as in most 

 other polyzoa." 



This view, I think, is incorrect. Intercalary zooecia could 

 not cause any inrreafie in size of the zoarium. There is a cer- 

 tain organic connection between all |iarts of a zoarium, Init it 

 is not such as would c^iuse the zoarium to swell in size if new 

 zooecia were intercalated among the others. From my examina- 

 tion of the various sj^ecies I find increase in size is made on the 

 margin of the flat, or nearly flat, species ; consequently, as in 

 all other disk-like forms, the zoaria grow from the centre to 

 the circumference. 



Tire conical Biporae grow from the apex to the l)ase ; I do 

 not say downwards because I believe that, when living, the i)ase 

 is uppermost. A proof of the correctness of this opinion is 

 shown in those zoaria which have the coral Dunoci/athus ])ar(i- 

 ■siticns growing on, or out of, their bases ; for it is impossible 

 that they could rest upon them, because the delicate tentacles of 

 the coral would be crushed, and the coral could not live under 

 such circumstances. Among the Jh'jxjrac dredged by H.M.C.S. 

 "Miner" were a few with this coral growing on them, and 

 through the kindness of Professor Spencer I have received some 

 Hpecimens of Bi povdc, dredged some 104 fathoms off the coast 

 of South Australia l)y Dr. Verco. of Adelaide, in which the corah 

 is imbedded in the zoaria, and also some sections of the same. 

 The sections show the base of the coral to be sometimes far 

 down in the zoaria, and that the zooecia formed subsequent to 

 the commencement of the growth of the coral have grown up 



1 Records of the Australian .Museuni, S.vdiiey, \<)1. vii., Xo. 4, li)(l!), p. 2(>7, et seq. 



