G. R. VINE ON THE FAMILY DIASTOPORID^. 



389 



and in the doing of this ... no better classification can be adopted 

 than that suggested by the same author, viz. into 1. Blastopores 

 simples; 2. B. env elopp antes ; 3. B. biserialaires. I propose, there- 

 fore, to term the simple Blastopore of Milne-Edwards Biastopora, the 

 enveloping or laminated forms Berenicea, and the biserial Mesenteric 

 pora"*. This arrangement Mr. Busk follows in his ' Crag Polyzoa/ 

 But Mesenteripora is placed as a genus of the Tubuliporidae, whereas 

 in the Museum Catalogue, part iii. Cyclostomata, it is placed as a genus 

 of the Diastoporidse. This I have no objection to, because it is only 

 those who have gone over the same ground who can possibly know 

 what difficulties there are to encounter in classifying the species 

 under discussion. The differences, however, between Mr. Busk and 

 Mr. Hincksf are very striking on this point. In the ' Catalogue of 

 Cyclostomata,' Mesenteripora (a foliaceous form of the Diastoporidse) 

 is included in the Family ; whereas in ' British Marine Polyzoa ' the 

 foliaceous forms are included in the genus Biastopora. This I entirely 

 object to, on account of the confusion it is sure to create when we 

 are dealing with Mesozoic forms. With this exception Diastopora, 

 in the sense in which I have used it, may be defined as follows : — 



" Zoarium adnate and crustaceous, usually discoid or flabellate, 

 less commonly irregular in form. Zooecia tubular, with an elliptical 

 or subcircular orifice, crowded, longitudinally arranged, in great 

 part immersed." 



The foliaceous species will have to be separately dealt with ; and 

 I think it very unwise to use the term Berenicea, as defined by 

 Lamouroux, for other than Paleozoic species. If Berenicea is used 

 for Palaeozoic and Oolitic species indifferently, simply because the 

 ¥ corallum incrusts foreign bodies " and is " composed of a thin cal- 

 careous base " confusion will be sure to follow, for the simple 

 reason that the characters of the Palaeozoic and Oolitic species 

 are altogether different. The Ceramoporce and Berenicea? of the 

 Palaeozoic rocks are not typical Blastopores. 



There now remain for investigation the Chalk- and Greensand- 

 forms ; and these I would gladly revise if Members would help me 

 by the loan of material for this purpose. Some of the species 

 catalogued are undoubtedly Blastopores; others are not Blasto- 

 pores in the restricted sense used by me in this paper. 



My thanks are due to kind friends who have assisted me with 

 material for the writing of this paper' — to Mr. Walford for supply- 

 ing me with extracts and tracings from Dumortier and Prof. Braun, 

 and to Mr. J. D. Longe, F.G.S., for the loan of specimens from the 

 Inferior Oolite. I also tender my thanks to Mr. R. Etheridge, 

 F.R.S., and to Mr. E. T .Newton, F.G.S., for allowing me to examine 

 the specimens in the Museum of Practical Geology. 



* Crag Polyzoa, p. 109. 



t British Marine Polyzoa, p. 457. 



X M'Coy, Brit. Pal. Foss. p. 44. 



Q. J. G. S. No. 147. 2 d 



