K. F. T0ME9 Otf MADEEPOEAEIA. 555 



30. On some new or imperfectly known Madeepoeaeia from the 

 Coeal Bag and Poetland Oolite of the Counties of Wilts, 

 Oxfoed, Cambbidgb, and Yoek. By Bobeet F. Tomes, Esq., 

 F.G.S. (Bead June 20, 1883.) 



[Plate XXII.] 



Inteodtjction. — I much regret that in the preparation of the present 

 paper I have not, as on the occasion of my former contribution 

 towards the history of the Madreporaria of* the Jurassic formation, 

 had the advantage of repeated personal investigations of the strata 

 from which the specimens were obtained. This expression of 

 regret, however, may perhaps seem unnecessary after the appear- 

 ance of the very ample and able paper on the Corallian rocks of 

 England by Messrs. Blake and Hudleston * ; but I would observe 

 that as their conclusions were drawn rather from the study of the 

 Mollusca and Echinodermata than from that of the Corals, we are yet 

 in ignorance respecting the exact stratigraphical position of the latter. 

 Consequently it is not by any means certain that the conclusions 

 arrived at by these geologists might not have undergone some 

 modification if the Corals had received more careful examination. 

 Possibly more than one Coralliferous period might have been 

 observed in the Corallian beds, just as more than one has been 

 pointed out in the Inferior Oolite ; and as some Madreporarian forms 

 are peculiar to the Coral Bag, it would be interesting to know more 

 fully than we at present do their range in time. 



It has always been a matter of some surprise that while the Coral 

 Bag of this country fulfils so completely the conditions of a Coral- 

 liferous deposit, and is in so many places crowded with Corals, the 

 number of species should be so small. MM. Milne-Edwards and 

 Haime f give ten genera and fourteen species, and this meagre list 

 has not since been added to, nor has our knowledge of the species 

 been augmented. Although Prof. Duncan has increased the number 

 of Great-Oolite Corals, he has made no addition to our knowledge of 

 those from the overlying Coral Bag ; and the very restricted number 

 of species at present known becomes the more remarkable when 

 comparison is made with the numbers which have been described 

 from beds of a corresponding period in Prance and Germany. It is 

 only necessary to turn to the works of MM. de FromenteJ, Becker and 

 Milaschewitch, and Quenstedt, to see how comparatively poor in 

 species is our Coral Bag. 



Possessed of but little additional information, I must content 

 myself with giving a section of the Coral Bag of one locality, and 

 determining the position of the Madreporaria therein, with alluding 

 to certain other localities, and noting the species therefrom, and 



* Quart. Journ. Greol. Soc. vol. xxxiii. pt. ii. p. 260 (1877). 

 t Brit. Foss. Cor. pt. ii. 



