D)'. G. J. Hinde — Discover// of Marsupites, etc. 483 



with the younger members of my family, on an evening in June, 

 and found, as Mr. Dibley had told me, that the greater part of the 

 Chalk had been refilled into the sewer-trench, and the residue had 

 been spread over the roadway and was now partly trodden down 

 by the traffic. We patiently broke a number of the remaining 

 blocks of chalk, and, in spite of the fact that Mr. Dibley had already 

 carefully worked at the place, succeeded in finding not only a couple 

 of plates of Marsupites with Ecliinocorys scutatus, etc., but also some 

 smaller inconspicuous plates which, when cleaned from the matrix, 

 proved to be test-plates of the unstalked, free-swimming crinoid, 

 Uintacriniis, Grinnell. These showed the existence at this place of 

 the lower portion of the Marsupites-zone, which has been designated 

 by Dr. Eowe ^ the " Band of Uintacrinus." 



Since last June another trench for sewerage, more than a mile 

 in length, and from 20 to 25 feet in depth, has been in course of 

 excavation along the northern half of Plough Lane, a road leading 

 from Purley to Beddington, to which I have made repeated visits 

 during the last two months, searching the Chalk exposed throughout, 

 and the subjoined list gives the names of the fossils obtained. 



The southern end of the trench is situated at the summit-level 

 of the Chalk ridge between Purley and Beddington, where the new 

 road mentioned above (known as Peak Hill Road) is given ofi", and 

 it is about 200 yards south of the Keeper's Cottage, shown on the 

 6 inch Ordnance Map. The summit is about 325 feet above O.D., 

 and from it there is a gentle slope towards the north, in the direction 

 of Beddington as far as where Plough Lane is crossed by the 

 Stafford Road, leading to Croydon, at a level of 193 feet O.D., and 

 at this point the trench stops. The entire area is included in the 

 boundary of Beddington parish. 



At the summit-level of the ridge the Chalk is near the surface, 

 being only covered by a few inches of brownish sandy soil, but 

 lower down the northern slope it gradually passes beneath beds 

 of brownish sandy loam, shown in the trench to a depth of 3-4 feet, 

 which represent the lower portion of the Eocene Thanet Sand, and 

 between the sandy loam and the Chalk there is in places a thin layer 

 of the unworn, green-coated flints, known as the Bull's Head bed. 

 The dip of the Chalk from the summit towards the north is probably 

 about the same as that of the general slope of the surface. As far 

 as can be seen, the Chalk in the Plough Lane trench is of the same 

 soft, white character throughout ; it contains but a moderate number 

 of black, solid, nodular flints, with a thin white crust, which, I am 

 informed, are principally from one layer, but small nodules are 

 occasionally present elsewhere in the beds. 



Fossils are very inequally distributed in this Chalk ; in some 

 parts of the section they are fairly common, whilst in others one 

 may sjjlit open a number of blocks without finding any. The list 

 given below is by no means complete, for the Microzoa have not 

 been worked out. In determining the various forms I wish to 



1 Proc. Geol. Assoc, vol. xvi (1900), p. 291. 



