1867.] DUXCAIS- A]S"D THOMSOX CTCLOPHYLLril. 327 



of the laminae would either leave them cleanly cut, or very irregularly 

 shattered. The edges of the strata of the hmestone hills of South- 

 east Devon, where they have not been left as cliffs or rocky projec- 

 tions, have either been planed down to a level sui^face, or smoothly 

 rounded off, the solid rock being often covered with only two or three 

 inches of loam or vegetable soil (excepting in fissures, grooves, re- 

 cesses, or valleys), as may be seen in the quarries near Torquay, and 

 on the line of railway between T^ewton and Totnes. 



^Tiatever theorj^ of denudation one may previously have enter- 

 tained, on coming to contemplate such phenomena it is sometimes 

 difS.cult to resist the impression that a great weight of solid matter, 

 powerfully propelled in a southerly direction, must have curved 

 back the slaty laminae, and, with an almost geometrical exactness, 

 rounded the forms of the limestone and other eminences of the 

 South-west of England. But so far as South-east Devon is con- 

 cerned, the mode of occurrence of perfectly preserved litJiodomous 

 perforations up to at least 240 feet above mean tide, as discovered by 

 Mr. Pengelly, and lately examined by myself, clearly shows that the 

 sea has been the last modifying agent to which the land has been 

 subjected *. 



JinfE 19, ia67. 



"William T. Lewis, Esq., Aberdare, South Wales, was elected a 

 Fellow. 



The following communications were read : — 



1. On Ctclophtllitm, a new genus of the CYATHOPHTLLn)^, with 

 remarks on the genus AuLOPnrvLLrx. By P. Maktix Dr:xcAiv^, H.B. 

 Lond., Sec.G.S., and James Thomsox, Esq., Y.-P. Geol. Soc, 

 Glasgow. 



[Plate XHI.j 



Contents. 



1. Introduction. 



2. Description of the genus Cyclophylluni and its species. 



3. Description of the species of AidojphyUum. 



4. The geological position of the Corals. 



1. Introduction, — A very fine series of specimens of the Palaeozoic 

 corals usually classified under the genus AulophyTlum f, llilne-Ed- 

 wards and Jules Haime, has been submitted by us to careful examina- 

 tion. IS'umerous sections of the specimens have been made, and espe- 

 cial attention has been given to the anatomy of weathered fossils of 

 the genus. Our examination has resulted in the determination that 

 the corals called AulojphyJlumfwiigites t and Aidoj)hi/JIum Boiuerbanhi 

 cannot remain in the genus Aulophyllum as established and defined 

 by Milne-Edwards and Jules Haime. Numerous specimens were 

 examined which had their cahces perfect ; and these gave evidences 

 of a columella, whose structure was revealed both by transverse and 

 longitudinal sections. One form, however, had no columella ; and 



* See a paper by the author in Geol. Mag. toI. iv. p. 296 (1867). 

 t Brit. Foss. Corals, Introd. p. Ixx (1850). 

 \ Hist. Nat. des Corall. vol. iii. p. 406. 



