286 Reports & Proceedings — Zoological Society of London. 



the small grains of pyrolusite and the type of false-bedding being 

 quite characteristic of desert conditions. The only footprints got m 

 the Annan Sandstones, also, are similar to those of the Trias, while 

 those of the Dumfries Beds belong to Permian reptiles. 



Mr. Peter Macnair read a paper on " The Hurlet Sequence in North 

 Lanarkshire". He described the succession of strata in the East 

 Kilbride, Carluke, and Strathaven districts, and pointed out that they 

 could be correlated bed by bed with those of the Glasgow basin, with 

 the possible exception of the Hurlet Limestone. He pointed out that 

 the Hurlet Limestone was not so constant as was supposed, and 

 that the Blackbyre ought really to be taken as the datum-line. 

 His co-relation with adjacent areas depended upon the occurrence 

 of the large form of Productus giganteus in the Blackbyre, the 

 Posidonomya corrugata bed above the Hosie, and the Nielson shell 

 bed above the Blackhall Limestone. He dealt particularly with the 

 section seen at Thorntonhall, and said that he had recently found two 

 Neilson shell beds there. 



III. — Zoological Society of London. 



March 23, 1915.— R. H. Burne, Esq., M.A., Vice-President, in the 



Chair. 

 Mr. R. Lydekker, F.R.S., E.Z.S., 1 presented a paper entitled "The 

 True Coracoid", in which he stated that the element in birds and 

 post-Triassic reptiles universally known as the coracoid is the 

 homologue of the human coracoid process, and its equivalent the true 

 coracoid of the monotremes and mammal-like reptiles. 



COERESPOISTD ENCE. 



CONCEKNING 'LATEEITE'. 



Sie, — The discussion on laterite that arose from a letter of mine 

 published some years 2 ago led to the appearance of a number of very 

 interesting papers in the pages of this Magazine, the latest being 

 Dr. Eermor's account of Professor Lacroix' work in Erench Guinea. 

 My own views on laterite were, I think, made sufficiently clear in 

 the discussion referred to, and I would not trouble you further were 

 it not for a point connected with Dr. Eermor's last paper. 



I have been engaged in the study of tropical weathering products 

 for some time and find that one of the difficulties is to prove, when 

 dealing with very fine-grained products, the presence of aluminium 

 hydrates mixed with hydrous aluminium silicate. On p. 127 of the 

 current volume of the Magazine Dr. Eermor mentions Mr. Edward's 

 paper in Economic Geology (ix, pp, 112-21, 1914) on the occurrence 

 of aluminium hydrates in clays, and after saying that the author 

 examined a large series of analyses of clays, adds : "The percentage 

 of bauxite thus detected in these clays." But no bauxite was 

 detected. What Mr. Edwards did was to assume that even if 



1 This was the last paper communicated by the author, who died on April 16, 

 1915. See Obituary, Geological Magazine, May, p. 238. 



2 Dated July 4, 1909 (see Geol. Mag., 1909, p. 431). 



