﻿62 ME. S. S. BTJCKMAN ON CERTAIN [Feb. I9IO, 



In the Blue Clay of Doghus l Cliff below the Bridport Sands, 

 species of Dwnortieria were obtained at 12, 40, 50 feet down and 

 right on top of the Junction Bed. 3 The names were noted many 

 years ago, and the specimens were fragmentary ; but a reference to 

 my Monograph on Inf. Oolite Ammonites (Palseont. Soc.) pt. v 

 (1890) will indicate the approximate forms. The really important 

 point is that they are more or less coarse-ribbed Dumortierice, and 

 that the 70 feet of blue clay can be dated as belonging to the hemera 

 Dumortierice : it is of later date than the Midford Sands of Bath, and 

 still later than the Cotteswold Sands of Gloucestershire, yet it is 

 earlier than the Bridport Sands of Dorset. 



Inland, in the lane-cutting from Symondsbury leading up to 

 Chideock Quarry Hill, this blue clay is not found on the top of the 

 representative of the Junction Bed : it has either passed laterally 

 into yellow sands, or it is absent. 



The Junction Bed lies below the clay. In its more complete 

 form it consists of five different layers of matrix, which occur in 

 regular order and can be easily separated one from another by the 

 chisel. The strata are those of striaUdus, a bifrons bed, a falcifer 

 bed, and two layers of marlstone down to spinatus : so that this 

 bed of about 2^ feet at the best, represents the lower part of 

 the Toarcian joined to Upper Pliensbachian. However, it is 

 seldom complete — the top, or the bottom, or a middle layer will be 

 wanting. The characters and coutents of this bed demand separate 

 treatment later. 



The following is a detailed section of Chideock Quarry Hill and 

 the cliffs (see also fig. 2, pp. 60-61) : — 



Section I. — Chideock Quarry Hill and the Coast. 3 



Thickness in feet inches. 



fuscce (1) Blue clay, capping the limestone . 10-12 



(2) ' The Limestone Beds.' 4 

 schlcenbachi ... (a) Grey crystalline limestone, with 

 bands of clayey marl in the lower 

 part. Par&insonia sp., stout form ; 

 Terebratula stephani 4 



(b) Similar limestone. ParJcinsonice 

 same as those in 2nd Bed of Burton 

 Bradstock 6 



(c) Earthy parting 2 



(d) Greyish limestone 1 3 



(e) Grey crystalline limestone, the 



lower part in massive blocks, about 8 



1 Doghus is the name of the cliff and of the farm in the valley behind it. 

 The name is printed as pronounced. A Yorkshireman might think that the 

 name referred to the sandburrs in the cliff which he would call ' doggers.' 

 A south countryman, with as little reason, supposes it to be a corruption of 

 'doghouse'; but a Welshman might perhaps have more right to claim the 

 name as a corruption of a Celtic term. 



2 See also Quart. Journ. Geol. Soc. vol. xlvi (1890) p. 519. 



3 It is sometimes called Chideock Hill, but this term is given by the 

 natives to the bill up the road to the west. Quarry (Qwor) Hill is the native 

 term for this eminence on the east. 



4 Quarrymens term. ' These are the only beds of stone fit for lime, the 

 other stone, if burnt, will not slake.' — Quarrymen's information. 



