Notices of Memoirs — E. von Toll — New Siberia. 31 



I. — Etude Miorographique du Tuffeau a Gyprina planata dit 

 NoRD DE France et de la Belgique, Du Eole des Diatomees 

 DANS LA Formation de ce Tuffeau (Notice preliminaire). Par 

 M. L. Cayeux, Freparateiir de Geologie a la Faculte des Sciences 

 de Lille. Annales de la Societe geologique du Nord, t. xix. 

 1891, pp. 90-95. 



THE Tuffeau described in this paper is a rock consisting of 

 glauconitio sands agglutinated together by a siliceous cement, 

 which is of not infrequent occurrence in the Sands of Landenian 

 age in many localities in the North of France and in Belgium. The 

 horizon of Gyprina planata appears to be slightly lower than that 

 of the Thanet Sands of this country. In some places, near Lille 

 for example, the rock is remarkably rich in zircon, tourmaline and 

 rutile. The author has also discovered therein abundant remains 

 of Diatoms and sponge- spicules ; the former principally belong to 

 the genera Syneclra, GoscinocUscas and Triceratium, whilst the latter 

 are chiefly of Monactinellid and Tetractinellid sponges. Sometimes 

 the Diatoms prevail in the rock ; at others the spicules. The silica 

 forming the cement of the rock may be either in the condition of 

 opal or chalcedony, and thus resembles the silica of the organisms. 

 The author considers that this cementing silica has, in part, if not 

 altogether, been derived from the remains of the diatoms and 

 sponges. In a subsequent note in the same journal (p. 134) mention 

 is made of the occurrence of Diatoms in the upper portion of the 

 Ypresian of Flanders, thus on the horizon of the London Clay. 

 From the character of the minerals in the Tuffeau and sands of the 

 Lower Eocene, the author concludes (p. 265) that they have been 

 primarily derived from the crystalline-schist series of rocks. 



G. J. H. 



II. — Paljeozoio Fossils from Kotelny Island, New Siberia. By 

 Baron Eduard von Toll. Memoires de I'Academie Imperiale 

 des Sciences de St.-Petersbourg, vii^ serie, vol. xxxvii. No. 3, 1889. 



THIS is the first portion of the Scientific Eesults of the Expedition 

 sent out in 1885-6 by the Eoyal Academy of Sciences for the 

 Exploration of Jana-Land and the New-Siberian Islands. Prefatory 

 remarks (pages 1-9) give an account of the Expedition, its aim, 

 progress, members, and helpers. A description of the fossiliferous 

 Devonian strata of the West Coast of Kotelny Island (pages 10-13) 

 precedes that of the fossils, which comprise 23 species and varieties 

 of Brachiopods, 6 Corals, and 2 Stromatoporoids. Eight forms are 

 peculiar to this region, and a table at p. 32 shows the distribu- 

 tion of the others in Siberia, West side of the Ural, Petchora-land, 

 Ehine-land, North America, or China, in the upper division of the 

 Middle-Devonian formation. 



The Silurian fossils, chiefly from the gravel of the Ssrednjaja river, 

 are 7 Brachiopods, 4 Trilobites, 6 Ostracodes (Leperditia), 12 Corals, 



