A. R. Horwood—Transition-bed and Crinoidat Limestone. 275 
Thus the southern portion which is free from Drift forms a series of 
winding sinuous escarpments right away from the Coplow to the 
south at Neville Holt, Hallaton, Medbourne, broken here and there by 
valleys now partially filled with Drift, or eroded by streams. And 
it has, furthermore, been lifted up by the Tilton—Loddington fault, so 
that some portion is now considerably out of its original position to 
the west. 
North of the Twyford brook the Marlstone in this central tract 
commences to form a bold feature to the west at Burrough-on-the-Hill, 
and in a less degree at Thorpe Satchville—but it forms a more 
continuous range of hills to the north-east of Burrough, where it 
constitutes the backbone of the ridge and connecting spurs, all classic 
hunting-ground, which stretch from Somerby, Pickwell, Knossington 
to Ranksborough and Whissendine—whilst near Owston it bends 
round to join the Tilton mass to the south. But except at Burrough 
Hill and a few other points the Rock-bed is greatly obscured by 
Drift, so that sections are few and far between. This, then, may 
be termed the central tract. 
In turn the most northerly Leicestershire massif is separated from 
the central tract by a line somewhat to the north of, but more or less 
parallel with, the Saxby and Bourne line from west to east, and 
extending from Holwell, Eastwell, Waltham, right up to Belvoir. 
It is connected by the Harby Hills, striking northwards from Long 
Clawson to Stathern, in the far north of the county. 
It is at Burrough-on-the-Hill, a place noted for its fine Roman 
encampment, which was earlier too probably a Celtic stronghold (and 
where now the Spring Parliamentary Steeplechases are yearly held), 
that the new discovery of the crinoidal limestone band has been made 
by the writer since the first paper (Gzox. Mae., April, 1910, p. 177) 
was in hand. The discovery is the more important as it relates to the 
central portion of the Marlstone outcrop, separated from the southern 
by a considerable distance. 
Though I had searched carefully for indications of this very 
characteristic bed (band 4 at Wildbore’s Lodge, Robin-a-Tiptoes, 
near Tilton’) at Burrough-on-the-Hill, I had until recently failed to 
find any indication of it. Except for an old trial-hole and obscure 
exposures, or slips covered with talus, no good section really existed 
on this extensive and well-known hill.* But in looking over some 
débris fallen from the higher ground on the northern extremity of the 
ridge, I discovered a curiously attenuated and modified form of the 
bed. This consisted of a thin sandy ferruginous rock with rounded 
and occasionally angular pebbles or inclusions of green and brown 
rock (chiefly Marlstone) and a few joints of crinoids. Evidently this 
was a conglomerate or brecciated conglomerate which represented the 
crinoidal limestone band at its western margin, at a period when that 
very constant, continuous stratum was being gradually elevated from 
the pelagic depths in which the normal highly calcareous band was 
being laid down. The marginal portion of this band lying in 
1 Vide J. W. Judd, ‘‘Geology of Rutland, etc.’?: Mem. Geol. Surv., 1875, 
p- 68. This bed may possibly be band 2 at Billesdon Brickyard (ibid., p. 69). 
* Since previous visits a small quarry has been opened, but in lower beds. 
