1870. ] JUDD—NEOCOMIAN. 327 
Oolitic series, by streams which probably flowed from W. to E. 
During the Glacial period this valley was filled with immense de- 
posits of the Boulder-clay and its associated beds; and on the re- 
emergence of the land from beneath the Glacial sea, the present 
rivers (the Derwent and its affluents), flowing from EK. to W. and 
cutting a narrow gorge through the harder strata of the Howardian 
hills, scooped out the valley again, but not to so great a depth as 
before*. Thus the clay-beds, which formed the bottom of the original 
valley, remain (especially in their eastern part) to a great extent 
concealed by drift-deposits, as represented in the ideal section 
(Pl. XXIII. fig. 1). 
Having pointed out the obstacles to complete examination of the 
inland development of the Neocomian beds of the district, I now 
proceed to describe in detail all the facts which I have been able to 
collect concerning them. 
The deep ravine (“gill”) formed by the small stream which 
flows by the village of Reighton, is cut quite through the Boulder-clay ; 
and about half a mile below the village, beds of blue clay were found, 
yielding Belemnites lateralis, Phil., and many fragments of Am- 
monites and Ancyloceras. These beds are shown by their fossils to 
belong to the upper part of the Lower Neocomian (zone of Am- 
monites spectonensis). 
From this point westward to the village of West Heslerton (see 
section, Pl. XXIII. fig. 2), a distance of fifteen miles, the base of the 
Wolds, as well as the bottom of the valley, is entirely covered and 
concealed by superficial deposits, and no opportunity is afforded for 
the study of the underlying strata. According to Young and Bird7y, 
however, a boring one and a half mile south of Staxton showed, 
under 278 feet of white and red chalk, beds of blue clay or shale, 
which were pierced to the depth of 54 feet. The general dip of the 
strata being S.H., as we proceed westward the beds underlying the 
chalk gradually rise, and at length are seen at the base of the Wolds, 
above the great superficial deposits which fill the bottom of the 
valley. 
In the western part of the parish of West Heslerton there were 
at one time several pits close to the Wold-foot, in which stiff blue 
clay was dug for dressing the loose sandy alluvial land of the dis- 
trict ; these, however, have been closed for many years, and I could 
obtain no evidence of fossils having ever been found in them. 
A little to the westward of these, however, on the boundary be- 
tween the parishes of West Heslerton and Knapton, there is a pit 
to which great interest attaches. At the bottom of a very deep 
chalk-quarry the underlying clay has been dug for the purpose of 
dressing the land. The section exposed was as follows :— 
* «The Hartford brook or river” (one of the tributaries of the Derwent) 
“rises on the very cliff near Filey, at a height of about 100 feet above the sea, 
and flows, westward, southward, and eastward, 100 miles before reaching it.”— 
Prof. J. Phillips, ‘ Rivers, Mountains, and Sea-coasts of Yorkshire,’ p. 85. 
+ ‘Survey of the Yorkshire Coast,’ p. 60 (1828). 
