BRITISH SILURIAN BRACHIOPODA. 



71 



' c' in Messrs. Roberts and Randall's section, 

 follows : 



Below this the section is described as 



f^" 



ft. ins 



d. Light-coloured grits, with plant-remains 20 



e. Hard micaceous grits, somewhat flaggy, and charged with Fish remains 



("The Upper Bone Bed ") 7 o 



f. Flagstones bearing current-markings 1 9 



g. Micaceous sandy grits with izn^w/^ 11 



h Greenish irregularly laminated rock with conglomerate 1 



i. Hard calcareous grit with thickly disseminated greenish grains and many 



broken Lingulce 1 



k. Laminated, light-grey, micaceous, and sandy shales 20 



Z. Grey micaceous grits 6 



m. Micaceous sandy clays coloured by peroxide of iron 6 



n. Yellow sandstones (Downton series), with Beyrichia, Lingulce; and including 

 two or more ferruginous bands, containing large quantities of the dermal 

 studs of Thelodus, fragments of Lingulcs, and minute crystals of quartz. 

 Clusters of Modiolopsis complanata occur at the base of this rock (The 



Lower OE Ludlow Bone-bed) 8 



o. Hard calcareous shales with Fish-remains, Lingulce, &c 6 



p. Flaggy beds of impure limestone, with Serpulites longissimus ; true Upper 



Ludlow 4 



q. Hard impure limestone ; Aymestry series ; at base. 



UPPER.SILURL\N SERIES OF SHROPSHIRE. 



Note. — The Localities are not all on the same line 0/ Section. 



<? S. "S =^ E. g to' g P o g g ° =' 



Lower Silurian^ 

 G. Maw delt. 



^Llando- 

 very. 



Wenlock Series 



Ludlow Series 



^Bevo7iian. 



Horizontal Scale— One Mile to an inch. 



" These are without doubt the passage-beds connecting the Silurian and Devonian 

 series ; and the only exception we take to Messrs. Roberts and Randall's determination 

 is the supposed occurrence of Amestry Limestone at the base of their section ; as, judging 



11 



