﻿204 DE. A. VATJGHAN ON THE PAL^ONTOLOGICAL [May I905, 



The railway lies nearly half a mile south of the town ; it cuts 

 2500 feet (measured horizontally) of Carboniferous-Limestone rocks 

 which dip almost due westward at an average angle of 44°. The 

 cutting exhibits a complete sequence, from the top of the Old Bed 

 Sandstone up to the lowest part of the 0^-subzone, but ends before 

 the LonsdaliaSiibzone is reached. 



In a new cutting, made through hard rocks entirely by blasting, 

 the utmost care has to be exercised that all the fossils recorded have 

 been found absolutely in situ. Loose material must be entirely dis- 

 regarded, since it may have been brought from any distance, dropped 

 from the trucks, and have reached its final position as the result of 

 subsequent blasting-operations. On the other hand, the loose material 

 in a quarry may, with more safety, be assumed to have been derived 

 from the beds exposed in the quarry. 



It is also to be remembered that, since a fresh cutting shows no 

 weathered surfaces, any fossils, but especially corals, are apt to 

 escape notice which, in the disused part of a quarry, immediately 

 arrest the attention. 



For these reasons the failure to record any particular species in 

 the Sodbury cutting cannot be considered to prove more than its 

 non-abundance. For example, no Clisiophyllid was recorded in 

 the cutting from the whole of the Seminula-Zoiie, whereas several 

 specimens from this zone were detected in the first quarry. 



Sodbury. 

 Tournaisian. 



Modiola-Zone (M). 



Lithological character. — Shales, grits, and calcareous bands 

 ending with a series of red limestones (Horizon a). 



Exposure. — The upper portion of the small Palaeozoic pro- 

 jection which is separated from the main Carboniferous Lime- 

 stone elevation by a broad valley, deeply filled in with the 

 Lower Jurassic strata. 



Fauna: — 



(1) From the beds below Horizon a. 



An ostracod is not uncommon (this is apparently the same as the 



common Avon species). 

 Fragments of a lamellibranch (possibly Modiola). 



(2) From Horizon a. 



Bhabdo?neson and fragments of crinoids are very abundant. 

 Cliothyris Boyssii. 



Correlation with the Avon section. — The few fossils 

 recorded above are all abundant at the same levels in the Avon 

 section. 



Cleistopora-Zone (K) . 



Lithological character.- — A well-marked 'Palate-Bed' at 

 the base, followed by a thick series of shales with subsidiary 

 limestones. 



