26 EEV. W. DOWNES OJf THE CEETACEOUS BEDS 



thins out to the eastward of Sidmouth ; and vaj own investigations at 

 Blackdown and Haldon will, I think, prove that at least the lower 

 two thirds of the Blackdown series have thinned out in the hiatus 

 which separates Blackdown from Haldon. 



I will here take the opportunity of saying, as germane to the present 

 subject, that I have a few additions to make to the list of Blackdown 

 and Haldon fossils published in the Quarterly Journal of 1882. 



In that list, under the head " Actinozoa," appears '' * SmiJotrochus 

 Austeni (E. & H.) [? Trodiosmilia] T. C." As regards the Black- 

 down form, I believe it ought to have been written " Trochosmilia 

 tuherosa (Ed. & H.) T. C. D."; but the specimens are not good, and 

 Prof. Duncan, to whom I showed them, would not be responsible for 

 their nomenclature. This species, or one closely approaching it, is 

 less uncommon at Blackdovm than has been supposed ; but it comes 

 from an horizon far removed from that of the Haldon corals, and 

 therefore should not be confused with them. I obtained five 

 specimens from bed 3 (see tabular view. Quart. Journ. Geol. Soc. 

 Feb. 1882, p. 84), whereas the Haldon corals, mostly compound 

 forms, are found in bed 13. 



After Inoceramus sulcatus, as Mr. Meyer has pointed out to me, 

 ought to be added J. semisulcatus. 



Nucula pectinata^ Sow., ? variety. This species is referred to 

 Blackdown in Morris's Catalogue ; but the actual specimen appeared 

 to have vanished from all known collections. I therefore omitted 

 this species in my list ; but I have since found it. Mr. J. S. 

 Gardner considers that my specimen more resembles those from 

 the Chalk Marl than those from the Gault. 



Solarium, clearly allied to S. ornatum, but (as Mr. J. S. Gardner 

 has pointed out) differing from Folkestone specimens " in the 

 absence of the distinct row of ribs ivhich extend about halfway across 

 the upper part of the whorl" The same correspondent informs me 

 that my specimens very closely approach a form from the Grey 

 Chalk. 



In the list of Haldon corals (p. 91) two of the commonest form? 

 have somehow been omitted. I allude to Astrocoenia decaphylla 

 (Ed. & H.) and Isastrcea haldonensis (Duncan). 



" Orbitolina-cheit " (bed 15). This, I am now inclined to think, is 

 no distinct bed, but merely a local variation from an ordinary 

 chert bed. 



I have also to add, from bed 13 at Haldon, Elasmostoma Norma- 

 nianum, of D'Orbigny. I am told by Dr. Hinde that this is one of 

 the calcareous sponges, since silicified, and that this species also 

 occurs at Warminster, and in the Tourtia at Essen-an-der-Euhr. 



Discussion-. 



Mr. Etheeedge generally confirmed the correctness of Mr. Downes's 

 section. He stated that a bed of " Carstone," from 1 to 2 ft. 

 thick, rests on the Lias of Black Yen. 



