Vol. 62.] PROCEEDINGS OF THE GEOLOGICAL SOCIETY. CXXXiii 



The following specimens, etc. were exhibited : — 



Photograph of Vesuvius and a map, exhibited by Prof. G. 

 de Lorenzo, For.Corr.G.S., in illustration of his paper. 



Specimens of dust, lava, and lapilli, etc., collected during the 

 recent eruption of Vesuvius, and a photograph, exhibited on behalf 

 of Arthur Collins by Prof. E. J. Garwood, M.A., Sec.G.S. 



Specimens from the Ordovician rocks of Western Caermarthen- 

 shire and lantern-slides, exhibited by D. C. Evans, F.G.S., in 

 illustration of his paper. 



An associated set of teeth of Ptyclwdus decurrens, Ag. (var. 

 depressus) in situ from the Holaster-subglobosus Chalk of Burham, 

 near Rochester ; and a quartzite-erratic (weighing 3 lbs.) from 

 the Chalk of Messrs. Martin & EarJe's Pit, Strood, exhibited by 

 G. E. Dibley, F.G.S. 



A copy of the rare 1844 edition of the ' Outline of the Geology 

 of the Neighbourhood of Cheltenham, by E. I. Murchison,' 

 exhibited by S. S. Buckman, F.G.S. 



May 23rd, 1906. 

 R. S. Hereies, M.A., Vice-President, in the Chair. 



The List of Donations to the Library was read. 



The following communications were read : — 



1. 'On the Importance of Halimeda as a Reef-forming 

 Organism ; with a Description of the Halimeda-JArnQstonGs of the 

 New Hebrides.' By Frederick Chapman, A.L.S., F.R.M.S., and 

 Douglas Mawson, B.E.. B.Sc. (Communicated by Prof. T. W. 

 Edgeworth David, B.A., F.R.S., F.G.S.) 



2. ' Notes on the Genera Omospira, Lophosjnra, and Turritoma ; 

 with Descriptions of New Species.' By Miss Jane Donald. 

 (Communicated by Prof. E. J. Garwood, M.A., Sec.G.S.) 



The Rev. H. H. Winwood, in exhibiting a series of water- 

 colour drawings of Mexican scenery, said that these 

 beautiful sketches were executed by Miss A. C. Breton, during 

 a recent visit to Mexico ; and, as the International Geological 

 Congress was about to meet in that country, she thought that some 

 of the Fellows might like to see them. They represented that iine 

 of active and extinct volcanos which stretches from the Gulf of 

 Mexico on the east to the Pacific Ocean on the west, including 

 Orizaba, Popocatepetl, Jurullo, and Colima. A short extract from 

 the publications of the Mexican Geological Survey, translated by 



