146 Geological Society. 



PROCEEDINGS OF LEARNED SOCIETIES. 

 GEOLOGICAL SOCIETY. 



November 20th, 1912.— Dr. Aubrey Strahan, F.R.S., President, 

 in tbe Chair. 



The following communication was read : — 



' On the Genus 'AulophyUum.' By Stanley Smith, B.A., 

 M.Sc, F.G.S., Clare College, Cambridge. 



Aulophyllvm is a genus belonging to the Clisiophyllid group. 

 It is found in the Upper Beds of the Carboniferous Limestone 

 Series in Britain and on the Continent. It appears in the lower 

 part of the DihutuyphyTlum Zone (Dj, becomes common in the 

 middle subdivision of the zone (D.,), and is plentiful in the highest 

 limestones investigated (D 3 ). 



The coral was first described by David Lire, in 1793, as Fungites; 

 the genus was established by Hilne-Edwards &, Haime in 1850. 

 The Author includes in this genus Thomson's genus Cyclqphyllum. 

 The genus is described in detail, and then the ontogenesis is 

 discussed. The development of the various items of coral anatomy 

 is first treated ; and the Author subsequently deals with the growth 

 of the coral considered as a whole, six stages being recognized by 

 him. The forms found in D l do not advance beyond stage d. 



Structural variation is then considered. The Author regards all 

 the species previously described as variations of the same species, 

 but recognizes several well-marked types and a number of time 

 mutations. Many specimens of the coral display the phenomenon 

 of rejuvenescence. The structural changes observed are described, 

 and the nature of the rejuvenescence is briefly discussed. 



December 4th, 1912. — Dr. Aubrey Strahan, F.R.S., President, 

 in the Chair. 



The following communications were read : — 



1. 'On the Lower Palaeozoic Rocks of the Cautley District 

 (Yorkshire).' By John Edward Marr, Sc.D., F.R.S., V.P.G.S. 



The following classification is suggested for the Ordovician rocks 

 of the district : — 



f Asbgill Shales. 



I Beds above the Volcanic Group. 

 Asiigillian. { Contemporaneous Volcanic Group. I Staurocephafi/s Beds. 



I Beds below the Volcanic Group. J 



( Pkacops-robcr/si Beds. 

 Caradocian. Calymene Beds. 



The Phacops and Calymene Beds are remarkably similar in litho- 

 logical characters (dark calcareous shales and impure limestones), 

 but the pakeontological change is at the top of the Calymene Beds, 

 and the fauna of the Phacops Bods is allied to that of the succeed- 

 ing strata. 



In addition to other fossils, the Asiigillian strata contain grapto- 

 lites, which have not been found, however, in the Ashgill Shales. 

 J)icelJogra/)(us chccjis Nich. comes in the Phacops Beds, and ranges 



