THE EED CHALK OF HUNSTANTON. 467 



this it is evident that, unless the genus is more rigidly defined than 

 it has been previously, it would be impossible to accept it for the 

 purposes of this memoir. By Eeuss (Bibliogr. 10, 11) and ISTovak 

 (Bibliogr. 34), and recently by Mr. Walford (Bibliogr. 30), the genus 

 has been accepted as a kind of passage-form between ^tomatopora 

 and Diastopora. There is, however, one peculiar species, Proboscina 

 spatiosa, in examples of which Mr. Walford traces varietal characters 

 so abnormal that, if disconnected fragments were found, and if growth 

 only was a consideration in the definition of a species, it could be 

 placed as a Tuhulipora, as a Diastopora, and even as an erect 

 Entalophora. Such instances, however, are rare, but I had already 

 noticed some of these abnormal features in material given to me by 

 Mr. Walford derived from the same locality (Inferior Oolite, 

 Shipton). In my new Cambridge- Glreensand material I have seen 

 a similar Froboscina (Entalophorian growth), but I have not noticed 

 examples similarly constituted in the lied Challi, except in one case 

 that will be referred to again further on. 



Jules Haime, in his admirable memoir on " Jurassic Bryozoa," 

 accepts Proboscina as a passage-group, and suggests that probably 

 Cellepora ecldnata, Goldf. (^=iTubulipora ecJiinata, Hag.), and 

 Siphoniotypliltis plamatus, Lends,, are really Proboscinal species ; 

 and Diastop)ora ramosa, Mich. (Lends. Bibliogr. 35) is undoubtedly 

 another. 



Mr. E. 0. Ulrich, examining some of Prof. Nicholson's species *, 

 places two of them in the Proboscina group. Thus Alecto confusa, 

 Nich., and Aulopora fronclosa, James, become Proboscina respec- 

 tively ; and Mr. Ulrich remarks that the Silurian forms are like 

 Stomatopora^ but with cells in two or more series t- As yet I have 

 not found the multiserial Proboscina in our own Silurian rocks, but 

 the antiquity of the genus is sufficiently established by the citation 

 given above. 



In determining new species and varieties for Eed-Chalk forms, 

 I have been desirous of not increasing the difficulties of the Palaeon- 

 tologist ; and in every case where I have called a species by a new 

 name, I have previously examined all the attainable illustrations 

 and descriptions by other authors before committing myself ; but 

 in the interests of truth I have preferred this course to promul- 

 gating false identities, which, to me, would be far more obnoxious. 



8. Pkoboscina ANGusTATA, d'Orb. Yarieties. (Plate XIX. figs. 1«- 

 Icl.) 



1852. Proboscina angustata^ d'Orb. Terr. Cret. v. p. 852, pi. 632. 

 figs. 7-9. 



1872. Proboscina angiistata, Reuss, " Bryoz. Unteren Planers," 

 p. 113, pi. 28. figs. 3, 4. 



1885. Stomatopora gracilis (?), Vine, Proc. Yorksh. Geol. 

 Polytech. Soc. vol. ix. p. 4, pi. 2. fig. 7. 



* Ann. Mag. IVat. Hist. ser. 4, toI. xv. 1875. 



t Journ. Cincinnati Soc. Nat. Hist. 1882, p. 149. 



