J. H. Cooke — Section in Middle Lias, Lincoln. 253 



resemblance to Endoceras-^orvus. It being impossible to refer these 

 species to any genus hitherto described, Kndoceras Burchardii may 

 be considered as the type of a new genus. As a suitable name I 

 propose Baltoceras, as the species of this genus appear in the Baltic 

 (Silurian. Baltoceras Burchardii (Dew.) is found in the Lituite 

 Limestone in the island of Oland and in Dalarne, as well as in the 

 corresponding horizon (Schicht Cj) of Esthonia, where I have dis- 

 covered it at Kandel, and at Hirro, near Keval. 



In the grey vaginatum Limestone in the island of Oland, and in 

 Dalarne, I have found a closely connected form with perfectly 

 identical structure of the ectosiphon, but with shallower loculi. 



In this connection it may be mentioned that there is reason to 

 suspect that JEndoceras, nov. sp., and Endoceras angmtisiphonatum 

 of Riidiger,^ far from belonging to the genus Midoceras, in reality 

 are some forms of Orthoceras, with marginal or submarginal siphon. 



III. — On a New Section in the Middle Lias of Lincoln. 

 By John H. Cooke, F.G.S. 



THE quarrying operations that have been carried out during 

 the last five years at Handley's Pit, Lincoln, have led to 

 the exposure of some very complete and instructive sections in the 

 Middle Lias. 



Handley's Pit is situate on the North Cliff, at a distance of about 

 a furlong from the now disused \nt of Glaisiers, and immediately 

 below that of the Lincoln Brick ComjDany (late Swan's). V/hen 

 compared with the sequence exposed in Swan's Pit, it affords some 

 interesting details that assist materially in clearing up some of the 

 doubtful points to which Mr. Dalton referred in the Geological 

 Survey Memoir on Lincoln Geology * regarding the limitation of 

 the range of A. margaritatus, and the occurrence of the Marlstone 

 Eock-bed in the Lincoln District. 



The general facies of the rocks exposed is a series of layers 

 of arenaceous shales, clays, limestones, and ferruginous nodules, 

 following one another rapidly and conformably, and having a dip 

 of 5° E. and 30° N. The line of dip as shown in the fall of the 

 section is, however, much distorted, a fact which is due partly to 

 the presence of a number of small faults, and partly to the unequal 

 shrinkage which the shales and clays probably underwent during 

 the processes of lithification. The following is the sequence that 

 the strata in this pit at present exhibit, the total thickness of which 

 is 35 feet 3^ inches. (See p. 254.) 



Many of these layers, however, are not persistent even over short 

 horizontal distances, and hence it is that no two pits in the district offer 

 the same sequence in their sections, and even in the same pit they 

 vary as the work of excavation proceeds. Mr. W. D. Carr ^ remarks 

 that at Lincoln the "Marlstone Rock-bed is entirely absent," and 



' Loc. cit., pp. 36-7, taf. i, figs, ba-h ; taf. ii, figs. lOa-5. 



^ Memoir of the Geological Survey, sheet 83, pp. 24 and 25. 



^ "W". D. Carr, " The Lincoln Lias " : Geological Magazine, April, 1883^ 



