ON FOSSIL POLTZOA. 255 



living species. These, Haime says, he could not find in the Caen Museum ; 

 consequently they are not determinable by their figures alone. The 

 Zoarium is adherent-encrusting, and formed of superimposed layers ; the 

 development commences in a simple manner, and is radiating or fanlike. 



The Diasiopora of Haime has a Zoarium with a large base, elevated, 

 foliaceous or frondescent, sometimes reticulated, formed of ascendant 

 leaves folding back upon themselves, and closely cemented in such a 

 manner as to present often two shelving planes of cells. Then the planes 

 are united by a laminated calcareous epidermis.^ 



Diastopora foliacea, of Lamx., covers two distinct types. One has been 

 well worked out by Professor Braun,- and upon this he seeks to estab- 

 lish the family Operculata, order Eleina, naming his type Elea foliacea. 

 The other species Milne-Edwards named D. Lamouroiixi ; and it forms 

 with D. Waltoni, Haime, the Diastopora simples of Edwards. The next 

 section of Haime and Edwards includes the whole of the Biserial species. 

 For these Blainville, in 1830, or rather for a section of the now recog- 

 nised species, founded the genus Mesenteripora, still retained by Busk in 

 the Crag Polyzoa and Cyclostomata,^ and in his list of Polyzoa collected 

 by Captain H. "W". Fielden (' Jour, of Linnjean Soc' 1880), and also by 

 Mr. Waters. Blainville's genus is again rechristened by D'Orbigny, and 

 becomes Bidiastopora ; establishing for the D. lamellosa a special genus 

 which, he calls Latero-multelea. 



Genus Diastopora, Lamouroux. 

 Sy. with Berenicea (pars), Lamx., ' Expos. Meth.' 1821. 



Hainae figures and describes five species of Berenicea and fourteen 

 Diastopora as present in the Jurassic series. I shall only notice those 

 species which are found in the British area. 



I have already, in a previous paper,* drawn attention to four types 

 of Diastopora {Berenicea, Haime), not previously noticed by authors. 

 They are 



1. D. stomatoporides, Vine. 3. D. oolitica, Vine. 



2. D. ventricosa ,, 4. D. cricopora „ 



These species range from the Lias to the Great Oolite ;. and for par- 

 ticulars, details, and description I refer the reader to the paper itself. 



Before leaving this purely descriptive part, I wish to speak of a 

 paper ' On the Relation of the Bscharoid Forms of Oolitic Polyzoa,' by 

 Francis D. Longe, F.G.S.^ In this paper Mr. Longe very ably discusses 

 certain peculiarities of cell- character, showing their apparent relationship 

 to the Escharoid forms of the Cheilostomata ; especially drawing the 

 attention of the palaeontologist to the opercula of the Oolite species. 



There are many discrepancies in our modern classification of the 

 Polyzoa ; and Mr. Longe has, by the publication of this paper, increased 

 our knowledge of their number. Seeing that the whole of the remarks 

 are founded upon facts gleaned from a comparative study of Oolitic 

 specimens, we cannot do more than accept the hints and illustrations, 

 and work them into our future histories rather than ignore them altogether. 



' Italics mine. 



* Die Bryozoa des Mittleren Jwa, 1879. ' BHt. Mus. Cat. pt. iii. 



* Further notes on the family JDiastoporida, Bnsk, Quart. Jour. Geo. Soc, August 

 1881. 



* Geological Magazine, January 1881. 



