CONTENTS— Cf?«//«?W. 



Memoirs : 



XI. Studies in the Morphogenesis of certain Pelecypoda : (2) The 

 Ancestry of Trigonia gibbosa. By Margaret Colley March, B.Sc. 

 Plate and J Text-figs, ---..-... pp. i — 12. 

 (Issued separately., April 20th, igti). 



XII. Some Physical Properties of Rubber. By Prof. Alfred Schwartz 



and Philip Kemp, M.Sc.Tech. With 11 Text figs. ■ pp. i — 22. 



UsiUid separately , May 2nd, igil). 



XIII. The Manner of Motion of Water Flowing in a Curved Path. By 



Prof. A. H. Gibson, D.Sc. pp. 1—5. 



(Issued separately. May 4t/i, igil). 



XIV. On the Periodic Times of Saturn's Rings. By Henry Wilde, 



D.Sc, D.C.L., F.R.S. pp. 1—3. 



(Issued separately. May Stli, /(?//). 



XV. Studies in the Morphogenesis of certain Pelecypoda : (3) The 

 Ornament of Trigonia clavelLita and some of its Derivatives. By 

 Margaret Colley March, B.Sc. With /j Text figs. pp. i— 13. 



(Issued separately. May jotit, igil). 



XVI. A Plesiosaurian Pectoral Girdle from the Lower Lias. By 



D. M. S. Watson, M.Sc W'itk 3 Icxtfigs. - pp. 1—7 



(Issued separately. May tqth, igii). 



XVII. The Upper Liassic Reptilia. Part 3. Microcleidus macropterns 

 (Seeley)and the Limbs of Miaodcidiis hoinalos/<oiidylus {OYre.n). 

 By D. M. S. Watson, M.Sc. il'ithj Tcxtfitgs. - pp. 1—9. 



(Issued separately. .'Hay igth, igii.) 



XVIII. Notes on some British Mesozoic Crocodiles. By D. M. S. 



Watson, M.Sc. I lit h .^ Text figs. pp. I— 13. 



(Issued separately. May 2gtti, igii). 



XIX. The Development of the Atomic Theory : (6) The Reception 

 accorded to the Theory advocated by Dalton. By Andrew 

 Norman Meldrum, D.Sc. pp. i — 10. 



{Issued separately, May 2<)th, tgn). 



XX. The Conditions that the Stresses in a Heavy Body should be 



purely Elastic Stresses. By R. F. Gwyther, M.A. pp. i— 12. 



(Issued separately, May 22nd, igii). 



Proceedings pp. xi. -jcxiii. 



