40 Reviews— M. Lohest — Devonian Fislies of Belgium. 



II. — Einige Bemerkungen ueber die Jura-Ablagerungen des 

 Himalaya und Mittelasiens. Von S. Nikitin. Neues 

 Jahrbuch fur Mineralogie, etc., 1889, Bd. II. pp. 116-145. 

 Eemarks on the Jurassic Strata of the Himalaya and Middle- 

 Asia. By Prof. Nikitin of St. Petersburg. 

 THE principal development of Jurassic beds in the Himalaya is on 

 the north-eastern slopes of the southern crystalline chain in the 

 neighbourhood of Spiti and Niti, where, resting on strata referred to 

 the Rhsetic and Lias, are the well-marked dark crumbling shales 

 known as the " Spiti shales." These shales are filled with phos- 

 phatic concretions, which have yielded a rich fauna, principally of 

 Ammonites, which have been studied and described by Oppel, H. F. 

 Blanford, Stoliczka, Waagen, and Neumayr. Very different opinions 

 have been expressed by these authors as to the relations of the 

 Ammonites to those in the Jurassic rocks of Europe and of Cutcli, 

 and consequently as to the relative geological horizon of the rocks 

 themselves ; but they have been generally reckoned as of the age of 

 the Kelloway and Oxford Clays, and supposed, more particularly by 

 Neumayr, to be related to those of the Russian and Polar Jura. Prof. 

 Nikitin has lately studied the two most important collections from the 

 Himalaya ; that of Schlagintweit at Munich, and of Strachey, in the 

 British Museum, and in this paper he discusses the characters of the 

 Ammonites and other fossils, and gives reasons for regarding them as 

 belonging to a younger horizon than hitherto supposed. The follow- 

 ing are the conclusions to which he has arrived : (1) The fauna of the 

 Spiti shales stand nearest to that of the Tithon and Kimmeridge 

 of Western Europe. Most of the Ammonites which up to now have 

 been considered as Kelloway and older forms represent much 

 younger types. (3) The differences between the fauna of Spiti and 

 that of Cutch may be easily explained on the supposition that the 

 fossil-bearing beds in the two regions do not represent synchronic 

 horizons. (4) The Himalayan Jura shows a far more significant 

 relationship to the Tithon of Southern Europe than to any Russian 

 Mesozoic formation. (5) The fauna of the Russian Jura on the 

 other hand is more intimately united to that of Cutch than to that of 

 the Himalayan Jura. (6) The assumed geological and geographical 

 connection of the Himalayan and Indian Jura with the Russian 

 Jurassic ocean, through the supposed Tarim basin, the Altai region, 

 and the great polar ocean, is as yet by no means proved. On the 

 other hand, there are many indications in favour of the connection 

 having taken place through the Amour region, Bokhara, Afghan 

 Turkestan, Khorasan, and the Aral-Caspian depression. 



III. — Fossil Fishes from the Devonian of Belgium. 

 " Recherches sur les Poissons des Terrains Paleozoiques de 

 Belgique." By Maximin Lohest. Ann. Soc. geol. Belg., vol. xv. 

 (1888), Memoires, pp. 112-196, pis. ii.-xi. 



THE remains of fishes discovered in the Devonian formation of 

 Belgium are all of a very fragmentary character, consisting 

 chiefly of detached teeth, portions of bones, and isolated scales ; 



