Reports & Proceedings — The Royal Society. 237 



successfully diverted from a westerly to an easterly drainage up to 

 and including the Jumna River. The author finds proof of the 

 recent date of the separation between the drainage-system of the 

 Indus and that of the Ganges in certain historical evidence, indicating 

 that the Jumna was a tributar}- of the Indus within the human 

 period; in the occurrence of the same species of freshwater porpoise in 

 the two river-systems and nowhere else outside of them ; and in the 

 identity of the freshwater Chelonia of the two river-systems, the 

 species being either peculiar to these drainage-areas or represented 

 outside of them by distinct varieties. 



4. March 26, 1919.— Mr. G. W. Lamplugh, F.B.S., President, in 



the Chair. 



At 6 p.m. a special general meeting was held in order to consider 

 the following resolution of Council: "That it is desirable to admit 

 Women as Fellows of the Society." 



The President said : It will be within the recollection of most of 

 the Fellows that the question of the admission of women to 

 candidature for the Fellowship of the Society has been raised on more 

 than one occasion in the past. It was considered in 1889 and 1901, 

 and again, more systematically in 1908-9, when a poll of the Fellows 

 was taken and three special general meetings were held, with 

 inconclusive results. 



It is generally recognized that the course of events since these 

 dates has materially changed the situation. Women have been 

 welcomed to our meetings as visitors, and we have had many 

 examples of their qualifications for Fellowship in the excellent 

 papers which they have from time to time contributed to the Society. 

 The value of these papers has been appreciated by all geologists, and 

 has been repeatedly acknowledged by the Council in its awards. 



Therefore, in the opinion of the Council, it is no longer reasonable 

 to maintain a sex-bar against qualified candidates for the Fellowship 

 of the Society, and I am empowered by the Council to submit the 

 above-mentioned resolution for your consideration. 



A ballot was then taken, and the resolution was declared carried 

 by 55 votes against 12. 



II. — The Royal Society. 

 March 27, 1919.— Sir. J. J. Thomson, O.M., President, in the Chair. 



The following paper was read : — 



"The Morphology and Evolution of the Ambulacrum in the 

 Echinoidea." By H. L. Hawkins, M.Sc, F.G.S. (Communicated 

 by Dr. Henry Woodward, F.R.S.) 



A summarized account of the ambulacra in non-Holectypoid orders 

 is given. Bothriocidaris shows the simplest type of structure, and 

 the most efficient for coronal strength. As podia increased, ambulacral 

 plates multiplied, and the areas became mechanically weak. The 

 main podial function in Regular Echinoids being adhesive, coronal 

 weakness demanded modification. In most Palaeozoic types, general 



