Notices of Memoirs — S/ierbom's Index Ainmalium. 519 



present clay, and we may infer that the enormously greater ice-covering 

 of the Glacial Period would exercise a much more powerful inhibition 

 on the monsoon of that period. The more extensive ice-sheet of East 

 Africa, by preventing abnormal heating of the land in summer, would 

 act still further in the same direction, and it is extremely probable 

 that the monsoon current partook of the southerly displacement of 

 the wind-system referred to above. The general result would be 

 a decreased precipitation over Abyssinia, and a much reduced Sobat, 

 Blue Nile, and Atbara, which at present account for 96 per cent of the 

 flood proper of the Nile. 



The geological history of the Nile entirely accords with the above 

 inferences. One of the chief results of the present monsoon rainfall 

 has been the deposit of finely divided muds brought from the 

 Abyssinian hills, in the Nile valley. To the south of Cairo these 

 deposits are at most of 80 to 35 feet thickness, of which 10 feet have 

 been laid down since the time of Ramses II. If conditions have 

 remained uniform, this would give a date fourteen thousand years ago 

 for the first deposits of alluvial muds in Egypt. Previous to this the 

 mud-laden waters of the Abyssinian Nile system did not reach Egypt, 

 just as the waters of Khor Gash now fail to reach the Nile,, and so 

 geology and meteorology concur in indicating a much weaker rainfall 

 in Abyssinia during the Glacial Period. 



III.— Index Generum et Specierdh Animalium. 1 

 Keport of the Committee, consisting of Dr. Henry WOODWARD (Chairman), 

 Dr. F. A. Bather (Secretary) , Dr. P. L. Sclater, the Eev. T. E. E. Stebbdng, 

 Dr. W. E. Hoyle, the Hon. Walter Eothschild, and Lord Walsingham. 



QINCE the 1910 Report systematic search through literature has 



proceeded up to the letter E. Eurther, a group of especially 

 troublesome and difficult books have been dealt with, e.g. : Oken's 

 Ids, 41 vols., 1817-48; Eroriep's Notizen, 102 vols., 1821-50; 

 Ersch & Gruber, Allgem. Encyclopaedic, 103 vols., 1818-50; and 

 many other volumes have been indexed out of the general order as 

 asked for or required — as, for instance, the works of Jacob Huebner, 

 which are now in Mr. Sherborn's hands in hope that he may obtain 

 some further information as to the dates of their publication. 



The search for rare literature continues, and Mr. Sherborn desires 

 to thank Dr. Karpinski for obtaining for him the second volume of 

 the Truditi of the St. Petersburg Mineralogical Society, 1831 ; 

 Dr. Bashford Dean and Mr. O. F. Cook for a complete set of Brandtia, 

 1896-7, both of which works will find a resting-place in the British 

 Museum (Nat. Hist.) when done with. He also desires to thank 

 Mr. Tom Iredale for much valuable help in obscure bird genera. 



The following papers have been written in connection with the 

 Index : — 



" On the Dates of Publication of Costa's Fauna del Regno di Napoli, 

 1829-86 " : Ann. Mag. Nat. Hist. (8), v, p. 132, 1910. 



" A Collation of J. C. Chenu's lllustr. Conch., and a note on P. L. 

 Duclos' Hist. nat. gen. et part, coquilles" (with Mr. Edgar A. Smith) : 

 Proc. Make. Soc, ix, March, 1911. 



1 Eead before Section D (Zoology), Brit. Assoc, Portsmouth, September, 1911. 



