438 J. F. Walker — Liassic Sections near Bridport. 



Lias on the sea-coast of Dorset. He describes it as " a remarkable 

 band of stone, the lower part of which is in a great part a con- 

 glomerate, the pebbles being imbedded in a more or less ferrugi- 

 nous matrix with Oolitic granules." " In places, however, this bed 

 assumes more the appearance of the Marlstone of other districts." 

 The higher part is composed of thin beds of a hard, dense, almost 

 chert-like, limestone, separated by thin laminse of yellow ochreous 

 clay, the whole being consolidated into one block ; he states the 

 thickness of the Marlstone and Limestone to be from two to three 

 feet ; that Ammonites serpentinum (falciferum) occurs in the lower 

 part of the Up})er Lias Limestone in some abundance, though badly 

 preserved, and considers denudation of that bed had taken place. 



This junction bed is also well described by H. B. Woodward, in 

 his valuable work on "The Geology of England and Wales," "as 

 a pink and cream-coloured limestone in the upper part, and a brown 

 nodular marlstone below." Mr. S. S. Buckman, in a paper (Quart. 

 Journ. Geol. Soc. 1890), refers to this rock, and states the limestone 

 of the fallen blocks is in two layers, Jlildoceras hifrons being 

 dominant in the upper layer, and Harpoceras falciferum in the lower. 



I have very little to add to these remarks on the sea-coast section, 

 except that I have found blocks of the limestone four feet thick, 

 generally cream-coloured in the upper and pink in the lower part, 

 and that the sandy part is sometimes a conglomerate, and at other 

 times a marlstone, as pointed out by Mr. Day. Blocks of this stone 

 were collected from Down Cliffs and under Thorncombe Beacon, 

 and used for building walls at Chideock, hence the fossils in old 

 collections are labelled from Chideock. 



The following are the Inland Sections which I have examined : — 



I. — The roadside cutting at North Allington below the brickfield 

 (1887) : 



A. Clay, worked as a brickfield. ft. in. 



B. (1) White limestone 8 



(2) Clay 1 



(3) Brown and red limestone 11 



(4) Marlstone 8 



C. Sandy Clay 3 2 



D. Brown sandy limestone, blue in centre ... ... 5 



E. About two yards of sandy marl, partly covered with 



grass and roadside scrapings ... ... ... 6 



F. Brown friable sandstone ... ... ... ... 2 1 



From the brickfield I obtained a block of stone, probably from 

 the next stone band, which contained Monotis incequivahis and 

 Ehi/nchonella amalthei. 



The fossils which I have been able to determine from bed D are : 



Rhjinchonella tetrahedra, var. North- 



iniipfoNomis. 

 Rhynchonclla furcillata. 

 Waldheimia {Zeilleria) perforata, var. 

 Spiriferina pingiiis. 

 Monotis iticequivalvis. 



Peden, sp. 

 Flicatnla spinosa. 

 Fholodomya ambigua. 

 Pleuromija costata. 

 Belemnites paxillosus. 



About one foot of the clay above this stone band contained the 

 same fossils, and others which were too imperfect to name. 



