Geological Society, 223 



refers, extends from the Peak Hill near Robin Hood's Bay to the 

 village of Saltburn near Redcar. The lias presents the threefold 

 arrangement of alum-shale, marlstone, and lias marl or lower lias 

 rock. 



The first of these deposits, the author says, consists of three di- 

 stinct divisions, viz. (a) soft, rubbly shale 130 feet thick, (b) hard 

 shale breaking into large lamellar blocks, 30 feet thick, and (c) soft 

 sandy shale from 15 to 20 feet thick. The upper part of the su- 

 perior bed of soft shale (a) is characterized by Ammonites striatulus, 

 A. communis, A.crassus, and Trigonia literata ; the middle portion, 

 from which alum is manufactured, by Ammonites Walcottii, A. he- 

 terophyllus, and Nautilus astacoides ; and the lowest by Ammonites 

 exaratus, A. elegans, Nucula ovum, and the remains of Saurians. The 

 hard shale (b) is distinguished by the presence of jet, Ammonites 

 elegans, Belemnites compressus, B tubularis, and Inoceramus dubius; 

 and the lower bed of soft shale (c) by the great abundance of Am- 

 monites annulatus. 



The marlstone, or second division of the lias series, is characterized 

 by Ammonites Hatvkerensis, A. Clevelandicus, A. Stokesii, Belemnites 

 conicus, B. elongatus, Turbo undulatus, Dentalium giganteum, Iso- 

 cardia lineata, Cardium multicostatum, C. truncatum, Corbula car- 

 dioides, Amphidesma recurvum, Mya V-scripta, M. literata, Pla- 

 giostoma Iceviusculum, Pecten equivalvis, P. sublcevis, Avicula incequi' 

 valvis, A. cygnipes, Plicatula spinosa, Modiola scalprum, M. Hillana, 

 and Terebratula bidens, T. subrotunda, T. tetrahedra, and T. tri- 

 plicata. 



The lower lias rock is distinguished by Ammonites planicosla, Pli- 

 catula spinosa, Hippopodium ponder osum, Lutraria ambigua, Pinna 

 folium, Gryphaa depressa y G. Maccullochii, G. incurva, Pentacri- 

 nites Briar eus, and P, vulgaris. 



In preparing these lists, the author says that he has omitted to 

 mention those fossils which he has not seen, or those which, from 

 their rarity, can be of little use in distinguishing the different sub- 

 divisions of the lias series ; and in conclusion, he states, that he has 

 found the fossils enumerated above, almost invariably in the beds to 

 which he has assigned them ; and he is of opinion that similar 

 sections may be drawn up on the same minute scale of the contents 

 of all the other strata, but that it remains for further investigation 

 to determine to what extent. 



A paper was afterwards read, entitled, " Observations on the 

 Loamy Deposit called Loess in the Valley of the Rhine," by C. 

 Lyell, Esq. For. Sec. G.S. 



In this paper Mr. Lyell details some observations made by him 

 in the summer of 1833, on the loess between Cologne and Heidel- 

 berg, and in several parts of Baden, Darmstadt, Wiirtemberg and 

 Nassau. Near Bonn large deposits of loess containing recent 

 shells rest on the gravel of the plain of the Rhine. The author 

 collected two hundred and seventeen entire shells, of which one 

 hundred and eighty-five individuals were of terrestrial species be- 

 longing to the genera Helix, Pupa, and Clausilia, and thirty-two of 



