378 VINE : POLYZOA AND MICROZOA OF YORKSHIRE AND NORFOLK. 
So far as I am concerned all that I have seen at all resembling 
the P. dilitata, d'Orb., is a cast of a species similar to the one re- 
ferred to in my Greensand paper. Its existence, however, is recorded 
by Prof Seeley in his 1864 paper, and by the Rev. T. Wiltshire, but 
marked rare (top layer Red Chalk). Therefore I retain d'Orb. name, 
so as to admit the identifications of Prof Seeley and the Rev. T. 
Wiltshire. 
Genus DiASTOPORA Lamx. 
The Diastopora of the Red Chalk are a very peculiar and a very 
characteristic group of fossils. Most of the species now to be referred 
to are alto^^^ether unlike any known British forms, but some are evi- 
dently allied to species described by d'Orbigny and other authors, 
derived from foreign Cenomanian or Senonian horizons ; while others, 
such as D. kimstantonensis and its allies are quite distinct and new 
to science. 
As already stated Prof Seeley has catalogued (1864) three 
species, Berenicea poly stoma Roem ; ly. contracta Seeley ; and B. 
Clementina d'Orb but in his 1866 paper only one species, B con- 
tracta Seeley is described. It is quite possible that this form may 
be one of the varieties of D. hunstantonensis Vine, of which species 
there are several varieties, and as no figures are given by the author 
it may be well to retain it, below which Mr. Seeley's remarks will 
appear. The other species I have not been able to identif)^ The 
CelluUpora sulcata Seeley will be retained as Diastopora, but I am 
not aware that I have come across a similar species in the Hunstan- 
ton Red Chalk . As Prof Seeley's fossils are preserved in the Wood- 
wardian Museum, probably labelled with the specific term sulcata, 
I feel that I have no right to suppress it in this memoir. 
23. Diastopora hunstantonensis, Vine. Fig. 7 (small example). 
1890. D. hunstantonensis. Vine, Quart. Journ. Geol. Soc, vol. xlvi., 
p. 475, pi. xix., figs. 10a, 10b. 
This is the most abundant and most characteristic of all the 
Red Chalk Polyzoa. I have found examples of it adherent to a large 
number and variety of fossils, especially the larger Ammonites. On 
♦ 1864 Ann. Mag. Nat. History. 
