682 MR. A. W. WATERS ON MEMBEANIPOEIDiE. 



however, I do not now consider that it filled up the opesial 

 space, and this opinion is based upon the similarity of the form 

 ot" the aperture with that of M. patellaria and its allies. In the 

 Crag and other fossil specimens, in some zooecia the aperture 

 is straight below, while others are distinctly bidentate ; and also 

 in the Capri specimens the aperture is generally straight, though 

 the dentate structure can often be distinguished or a broad 

 denticle may be formed in the middle, the front wall slopes 

 down to the distal end. 



The whole of the surface of the zooecia and of the ovicells is 

 minutely granulate. The ovicell is small and but slightly raised, 

 and has a perforation at the top. There are about 6 lateral 

 rosette-plates. 



This belongs to a group that was largely represented in the 

 Cretaceous and Tertiary periods ; but the genus PeriteicMsma of 

 Koschinsky contains species not closely allied, and if a genus has 

 to be made it must be upon other grounds than those given by 

 Koschinsky. 



Loc. Living : Capri, from 220 metres. Eossil : Cretaceous of 

 Ciply, Maestricht, and Foxe ; Miocene of Australia ; Pliocene, 

 Italy, Sicily, Khodes, and the Crag. 



Membbanipoea patellaeia {Moll). 



Diachoris patellaria, Waters, Ann. ^ Mag. Nat. Hist. ser. 5, vol. iii. 

 p. 120, pi. X. figs. 6-9. 



Membranipora patellaria, Waters, Q. Journ. Geol. Soc. vol. xlvii. p. 13. 



Adriatic and Naples ; Madeira (J". T. J. coll.) ; Elorida. i'ossil : 

 the Bartonian of North Italy. 



Membeakipoea patellaeia, var. mttltijuncta, Wafers. 



Diachoris patellaria, var, multijimcta, Waters, Ann. 8)" Mag. Nat. Hist. 

 ser. 5, vol. iii. p. 120, pi. xiii. fig. 4. 



Amphiblestrum patellarium, MacGillivray, Zool. Victoria, decade xii. 

 p. 70, pi. cxvii. figs. 9, 10. 



Adriatic and Naples ; Yictoria. 



Membeanipora papillata {Busk). 



Amphiblestrum papillatum, Busk, Zool. Cliall. Exp. pt. xxx. p. QQ, 

 pi. xxxiii. fig. 1. 



Membranipora trifolium, form minor, Hincks, Ann. (§• Mag. Nat. Hist, 

 ser. o, vol. xv. p. 255, pi. viii. fig. 7. 



I am not quite sure that the Membranipora first described by 

 Hincks from Bahia, as M. trifolium form minor., is the same as 

 what he subsequently figured from Tahiti under this name, but 



