40 



apparently an upthxow of the New Red and Rhsetic Series 

 against the Planorbis beds of the Lower Lias, which are about 

 50 feet above the sea level, the northern faiilt is nearly concealed 

 by the sea, and_far out on the fore-shore. The great St. Decumans 

 fault is south of these, but parallel — as all the east and west 

 fractures are. This one, however, exhibits no effects along its 

 line or bearing. The known thickness of the Ehsetic series in 

 the section immediately west of Watchett, and in which the 

 Microlestes was found, is about 50 feet ; that to the east of the 

 Harbour, about 200 feet. The specimens collected by W. B. 

 Dawkins, Esq. from these two sections were submitted to me 

 for determination in 1864. I purpose embodying them with 

 those recognized at St. Audrey's slip, &c. in a tabular form, 

 so as to exhibit the whole fauna at once. I also append the 

 description of St. Audrey's vertical CHff Section showing suc- 

 cession of the groups as determined a few years since. 



St, Atjdeey's Section. 

 VI. 



The most complete section of the Rhsetic series in Somerset- 

 shire, if not in the west of England (except Penarth), is perhaps 

 at St. Audrey's SKp, east of Watchet, where the whole series 

 are admirably exposed in one cliff section, ranging from the 

 Tea Green Marls, through the Black Rhsetic Shales to the 

 Bucklaudi Beds, (the Bucklandiand Lima series.) The Ammonites 

 Planorbis and Ostrea Beds, and the white Lias which cap the 

 shales, and the Tea Green series at the base are all conspicuous 

 in the section. 



The details of the Section may be read either upwards or 

 downwards. I piu'pose, however, briefly describing the groups 

 in upward succession. The measured section in full detail was 

 constructed some years since, at a time when the Black Shales 

 were in better order than at present ; the sea having made 

 extensive ravages and changes in its aspect. 



At the slip, or road from the shore, the uppermost members 

 of the new Red Marls are exceedingly well shown, and also the 

 transitional series called the "Tea Green Marls," which measure 



