W. F. Sume — Notes on Russian Geology. 549 



basals are unequal in size, and form a rude, quadrilateral, cup-sliaped 

 figure which extends a little more than one-third up the sides of the 

 calyx. The point of attachment of the stem is small. 



The four radials are large, with the usual expansion above to 

 enable them to accommodate themselves to the form of the calyx, 

 their mean length and breadth being nearly equal. The excavation 

 for the arm occupies more than one-third the breadth, and its depth 

 bears about the same proportion to the length of the plate. 



The inter-radials occupy the spaces exactly between the arms, 

 and apparently have two shorter lower sides and two longer upper 

 sides which therefore meet at a more acute angle. 



The vault is flattened, quadrate, and composed of a few large 

 polygonal plates each bearing a prominent central tubercle, which 

 is especially large at the base of each arm. 



In this specimen the arms are wanting, being broken off close to 

 the calyx. 



It has been thought that it might be of use to place on record the 

 occurrence of this abnormal form in view of the discussions still 

 going on in regard to variations in recent types. 



VII. — Notes on Eussian Geology.^ 



By W. P. Hume, B.Sc, A.R.S.M., F.G.S, ; 



Demonstrator in Geology, Eoyal College of Science. 



II. The Loess : Its Distribution and Character in S. Eussia. 



COVEEING a vast extent of the southern portion of Eussia in 

 Europe, occurs the sandy clay which is commonly known as 

 Loess, whose origin has given rise to the most varied and conflicting 

 opinions. In the coarse of a visit to the above country, this deposit 

 struck the writer as well worthy of further study, whilst its connec- 

 tion with the Black Earth invited closer inspection. Its distribution 

 and general characters, as regards the greater part of Western and 

 Central Europe, have been dealt with in a most masterly manner 

 by Baron von Eichthofen in his " China," chap, v. ; but at the 

 Eussian frontier his description ceases almost abruptly, and he 

 merely mentions that the Dniester and its tributaries appear to have 

 cut their channels through the Loess. 



The statements about to be made apply especially to this deposit 

 as it occurs in the Governments of Podoba, Kieff, Kharkoff, Kursk, 

 Ekaterinoslav, Poltava, Tchernigov, and the Don Cossack country, 

 districts which more or less came under my immediate notice. (For 

 map of region see Geol. Mag. September, 1892, p. 387.) As else- 

 where, so here it occupies the highest position in the geological 

 sequence, lying unconformably on all the principal formations. To 

 the W. of the Dnieper it hides beneath itself the broken and contorted 

 gneisses and granites of the Archaean axis, in S. Ekaterinoslav and 

 the Don Cossack country it covers the shales and sandstones of the 

 Carboniferous, whilst in the more central governments of Kursk, 

 Kharkoff, and Tchernigov it overlies the Cretaceous and the whole 

 1 For No. I., Cretaceous, see Geol. Mag. September, 1892. 



