December 22, 1923] 



NA TURE 



919 



ihc papers which he has published already, together 

 \Mth the work especially of Dr. G. de P. Cotter, are 



licient to permit of a satisfactory classification of 

 c Burma TertiaHes, the correct correlation of which 

 is of great importance to the petroleum industry of 

 the province. Of the dist-nct steps forward, one of 

 the most important has been recognition of the 

 precise nature of the lateral variation in fades, 

 especially that from north to south, in consequence of 

 the progressive rise and silting of the meridional 

 marine gulf which existed to the east of the Arakan 

 hills in early Tertiary times. Extended mapping of 

 the formations shows how freshwater formations in 

 the north pass southwards into beds of marine origin, 

 while estuarine and littoral beds pass into those of 

 more settled marine origin. The papers of Messrs. 

 Vredenburg and Cotter published in the Records of 

 the Geological Survey (vols. li. and liv.) bring together 

 the main results of this work expressed in tabular 

 form, and additional details have just been issued in 

 a posthumous paper by Mr. Vredenburg (vol. Iv., 

 part I, 1923)- 



The correlation of the Burma Tertiaries with other 

 areas has been based mainly on marine fossils, but, 

 meanwhile, most valuable studies of the vertebrate 

 remains included in freshwater beds have been carried 

 on by Dr. G. E. Pilgrim. Most of this has been in 

 connexion with the younger Tertiaries of the famous, 

 but, as it proves, not entirely well-known, localities 

 of the west and north-west. Recent work in the 

 Punjab Salt Range shows that some revision of the 

 correlation tables will be necessary, and that it will 

 be possible, when the newly discovered vertebrate 

 remains are studied, to correlate by direct fossil 

 evidence the lower and middle Siwaliks of the Salt 

 Range with those of the Himalayas. 



The director's report of the Survey for 1922, just 

 issued by Dr. E. H. Pascoe in the Records, describes, 

 besides a summary of Dr. Pilgrim's most recent work, 

 some interesting results in other parts of India, in 

 addition to those separately noticed in previous pages 

 of Nature. Among these, an interesting discovery 

 of true Gondwana coal has been made in the Southern 

 Shan States, indicating a Jurassic or Rhaetic age, 

 corresponding to a part of the upper division of the 

 Gondwana system in India and some of the coal beds 

 of Tonkin. 



Considerable additions have also been made 

 recently to our knowledge of the Deccan trap and of 

 the dykes through which the lava attained the sur- 

 face. ' Recent work by Mr. H. Walker in the Tapti 

 valley reveals the interesting fact that the river, for 

 more than 30 miles in an east-west line, follows a 

 fault valley, roughly parallel to the general tendency 

 to rifting which Sir Thomas Holland referred to in 

 his presidential address to Section C (Geology) of the 

 British Association at the meeting in Australia 

 (Nature, vol. xciv., September 3, 1914, p. 8) as a 



{)reparatory condition for the outflow of the Deccan 

 ava sheets. 



Another feature of general interest arises from the 

 long-delayed analyses of brines from the Sambhar 

 lake in Rajputana. The economic question which 

 led to a special investigation of this lake 20 years ago 

 arose from the observation of the salt-manufacturing 

 officers that the lake showed signs of depleted re- 

 sources and consequently possible loss as a source of 

 Government revenue. The investigation undertaken 

 in 1903 by the Geological Survey showed that, while 

 the total amount of sodium chloride stored in the 

 silt rendered nervousness on this account unnecessary, 

 there was a possibility that the continual removal of 

 pure chloride as salt and the consequent increase in 

 the proportion of residual carlwnate and sulphate 



NO. 2825, VOL. I 12] 



among the soluble salts might increase the difficulty 

 of customary manufacture by fractional crystallisa- 

 tion. A methodical system of sampling was then 

 undertaken annually from various parts of the lake, 

 and Dr. W. A. K. Christie has recently analysed the 

 products. A summary of his results shows that there 

 was a small but definite deterioration in chloride as 

 the result of ten years' work in extracting salt between 

 1907 and 19 16. Taking the two five-year periods to 

 tone out annual variations, the ratio of chloride to 

 other soluble salts in the lake brine has dropped from 

 86'09 : i3"9i to 85-38 : 14-62. In the brines obtained 

 from the sublacustrine silt the corresponding ratio 

 has fallen from 83-18 : 16-82 to 81-07 '■ 18-93. Ar- 

 rangements have been made for resuming the annual 

 sampling of the brines ; for unless a system be devised 

 for recovering some of the other salts, the value of the 

 lake as a source of salt will cease long before there is 

 any approach to exhaustion of the total supplies. 



Palaeontology at the American Museum 



of Natural History, 



T^HE researches of the palaeontological department 

 ' of the American Museum of Natural History 

 for the years 19 18 to 1921 have now been issued as 

 a volume, making the seventh in the series. In all 

 there are twenty-three papers, contributed by Prof. 

 H. F. Osborn, Dr. Matthew, Dr. Gregory, Messrs. 

 Granger, Mook, Von Huene, Miller, Gidley, and Camp. 

 Prof. Osborn describes some new Titanotheres, mostly 

 primitive forms, from the Huerfano, and in two other 

 papers continues his studies on the Proboscidea. One 

 is an account of some American mastodons, and the 

 other is important as giving his views to date on the 

 evolution, phytogeny, and classification of the elephant 

 group as a whole. Dr. Matthew, in addition to 

 faunistic papers, continues, with Mr. Granger, the 

 review of the faunas of the Eocene deposits of the 

 United States. The papers by Messrs. Gidley and 

 Miller are faunistic. There is a series of ten papers 

 by Mr. Mook on crocodiles, recent and extinct ; a 

 paper by Mr. Von Huene on reptilian and stego- 

 cephalian remains in the Cope collection ; and three 

 by Dr. W. K. Gregory, one of them in collaboration with 

 Mr. Camp, which are continuations of his studies on the 

 comparative myology and osteology of vertebrates. 



In considering these contributions to our knowledge 

 of palaeontology, for the value of which the authors' 

 names are a sufficient guarantee, it will be noticed 

 that the bulk of them are continuations of previous 

 studies, and are designed to attack definite problems. 

 Such, for example, is the series by Dr. Gregory on 

 the muscles and bones, where various parts are 

 compared one by one and worked out in a most 

 systematic manner. These papers will form a mine 

 for other workers. In the same spirit is Mr. Mook's 

 intensive study of the crocodiles and Prof. Osborn 's 

 on the elephants. 



The volume is a worthy memorial to the energy 

 and devotion of the president and staff of the museum, 

 and the museum without doubt gains from this 

 advertisement of its activity. If the publications by 

 members of the staff of the palaeontological depart- 

 ment of the British Museum for a similar period were 

 gathered together, it is probable that they would 

 make a worthy companion volume, but, being widely 

 scattered in several publications, the public has never 

 the opportunity to discover this fact. 



It may further be noted that, in the period covered 

 by these communications, the American Museum from 

 its palaiontological department alone sent six expedi- 

 tions into the field as far as China, India, and Cuba, as 

 well as in the States themselves. 



