ON FOSSIL POLTZOA. 117 



92. Cribrilina moxoceros, Busk (non Reuss) = Lepralia ibid., Bask, 



' Mar. Poly.' p. 72 = Lepralia ibid., MacGill., ' Zool. Vict,' 

 decade iv. p. 32 = Cribrilina, Hincks, ' Proceed. Lit. & Phil. 

 Soc. Liverpool,' April, 1881 ; ' Ann. Mag. Nat. Hist.,' July, 1881. 

 Range. — Living : Bass's Straits. Fossil : Baimsdale (Gippsland). 



Genus Membeaxiporella (part), Smitt. 



Rerenicea, (part) Flem. ; Lepralia, (part) Johnston, Gray, Busk ; 

 Membranipora, (part) Smitt. 



' Zoarium incrustiug, or rising into free, foliaceous expansions, with a 

 single layer of cells. Zooecia closed in front by a number of flattened 

 calcareous ribs more or less consolidated.' — Hincks, 199. 



93. Membraniporella nitida, Johnst. (Hincks, p. 200) = Escharoides 



ibid., Milne-Ed. =Rerenicea ibid., Flem. ; M. nitida, Waters. 

 ' Quart. Jour. Geol. Soc.' vol. xxxix., p. 436 ; Lepralia eximia, 

 Seguenza, ' Le Form. Terz. R. Accad. dei Lincei ; (?) Pliophlcea 

 sacjena, Gabb & Horn, Monogr. (Cret. Bry. New Jersey). The 

 authors give the following synonyms for this species = Flustra 

 sagena, Morton, ' Synopsis, 'p. 79, pi. 13, fig. 7; Escharina ibid., 

 Lons. ' Quart. Jour. Geol. Soc' vol. i. p. 71 ; Reptescharinella 

 ibid. D'Orb, ' Pal. Ft.' v. p. 429. 

 Range. — (?) Cretaceous, Timber Creek, New Jer. ; Waurn Ponds, 



Australia (Waters) ; Zanclean Calabria (Seg.). Living: Northern Seas ; 



Capri, 225 fathoms (Waters) ; New Zealand (Hutton). 



Family XI. Microporellim, Hincks. 



Celleporidce, (part) Johnst.; Membraniporidce, (part) Busk; Porinida} 

 (part) D'Orb. ; Eschariporidce, (part) Smitt. 



• Zoaicia adnate and incrusting- or forming: erect and foliated or 

 dendroid zoaria ; orifice more or less semicircular, with the lower margin 

 entire; a semilunate or circular pore on the front wall.' — Hincks, p. 204. 



This important family group is founded upon well-marked structural 

 features, one of which is the ' semilunate or circular pore,' in the front 

 wall, given in the diagnosis. Mr. Hincks indeed says, ' We do not know 

 the physiological import of this definitely shaped opening .... but 

 the character which is constant may be fairly accounted of considerable 

 importance, and taken in combination with the form of the aperture is a 

 good diagnostic mark,' (I. c. p. 205). Further particulai-s of this mark 

 are given by Mr. Waters (' Quart. Jour. Geol. Soc.' vol. xxxvii., p. 313). 

 He says, ' In studying both recent and fossil forms, I have often been 

 impressed with the frequency with which open pores are replaced by 

 avicularia, and think that it is a matter worthy of most careful examin- 

 ation.' Mr. Waters says, however, that the 'genus Microporella must be 

 extended ; for we are able to trace relationship from M. violacea with a 

 round pore to the variety jissa with an elongated pore (fig. 7'S). Then 

 we have M. Yarranensis with two or three denticulated pores in the 

 depression, and, in this way on by M. coscinopora and var. armata to 

 M. symmetrica (fig. 83).' The fossil Microporellidce are well represented 

 in the Australian deposits, and the necessarily reduced number of generic 

 features in the group has increased the number of synonymous names ; 

 but in spite of this, the three genera which Mr. Hincks includes in the 

 family, in his ' Brit. Marine Polyzoa,' are well marked and easily 

 identified. 



