Correspojidcncc—Pt'ofessor T. G. Bonnoij. 9;") 



build up the rock, and by the inclusion of one mineral by another. 

 Porphyritic felspars are recorded from several localities. 



The author concludes that the rocks of Section V are nearly related 

 to those described in the earlier part of the paper, and points out the 

 close resemblance of the whole to the Charnockite Series of Southern 

 India. 



2. " Note on the Occurrence of Corundum as a Contact-Mineral at 

 Pont- Paul, near Morlaix (Finistere)." By A. K. Cooraara-Svvamy, 

 Esq., B.Sc, F.L.S., F.G.S. 



The intrusive granite of Pont-Paul, near Morlaix, contains highly 

 altei'ed fi-agments of sedimentary rock. The minerals found in 

 them are biotite, muscovite, corundum (first recorded by Professor 

 Barrois in 1887), plagioclase, andalusite, pyrite, magnetite, silli- 

 nianite, green spinel, and zircon. The corundum forms sharply 

 idiomorphic tabular hexagonal crystals, striated and slightly stepped 

 on the basal plane, and blue in colour. Iron-oxide is a constant 

 inclusion. The inclusions have probably been to some extent 

 injected with felspathic material. The original sediment was 

 probably poor in silica and rich in alumina, and there has been 

 sufficient molecular freedom for the formation of well-shaped crystals 

 of corundum, comparatively free from inclusions. Sillimanite and 

 zircon are the only other minerals which exhibit crystalline form. 



G o 12, s,ESi=>oisrnDEisrc s . 



YORKSHIRE BOULDERS. 

 Sir, — The value of IVlr. Stather's paper on the sources and dis- 

 tribution of Yorkshire boulders (p. 17), which is very great, is not 

 enhanced by the concluding paragraph. The Scandinavian Ice-sheet 

 seems to affect some geologists as King Charles' head did Mr. Dick. 

 ]\Iay I then ask Mr. Stather two questions :—(l) What route did 

 the Scandinavian Ice-sheet take when it anticipated the Norsemen 

 by invading England? (2) What caused it to retreat before the 

 advance of the British Ice-sheet ? It was no doubt very polite to 

 give place to the ' weaker vessel,' but as the British hill districts 

 are smaller than and to the south of the Scandinavian, I should have 

 thought nature would not have allowed courtesy to supersede law. 



T. G. BONNEY. 



FREDERICK WILLIAM EGAN, B.A. 



Lorn July 31, 1830. r>iKi> January G, 1!)01. 



Mr. Egan was born in Dublin on July 31st, 183G, and was the 



third son of the late Mr. W. J. Egan, of Rockville, Dundrura. 



Receiving his early education at Mr. Flynn's school in Harcourt 



Street, he entered Trinity College, where in due course he took 



