Vol. 69. 



PALAEOZOIC ROCKS OF THE CAT7TLEY DISTRICT. 



is seen in the stream-bed. It is unweathered, and I could find 

 no fossils in it ; but it probably represents an important band in 

 Watley Gill and Oddgill, described elsewhere. 



The Ashgill Shales of Backside Beck are not very fossiliferous, 

 save the bands with Phyllopora hisingeri and Myelodactylus near 

 the top. Strophomena sihiriana Dav., with other brachiopods, and 

 Phacops mucronatus Brongn., are not infrequent. I believe that all 

 records of Trinucleus from the Ashgill Shales of this stream refer to 

 specimens obtained from lower beds, which have hitherto been partly 

 referred to the Ashgill Shales. 



Before leaving the beck, I may say that I doubt the identification 

 of Phacops brongniarti which I previously made. The specimen is 

 unfortunately lost. 



To sum up, the Backside-Beck section gives us the following 

 sequence : — 



Upper : Ashgill Shales (with Phyllopora Beds near the top). 

 /Beds above the volcanic 



Asiigillian 



Caradocian 



Middle : StaurocephcUus Beds 



Lower : Phacops-robertsi Beds 



I group. 



J Contemporaneous volcanic 

 I group. 



j Beds below the volcanic 

 V group. 



Calymene Beds. 



Confirmatory Sections. 



Watley Gill. — Starting from the junction with Backside Beck, 

 the Phacops-robertsi Beds are exposed for a few yards up the tribu- 

 tary in its wooded portion, and pass up into blue flags, which are 

 well seen opposite the sheepfold, and continue for many yards up 

 stream. These are the beds below the volcanic group. They have 

 yielded Climacograptus normalis, with crushed brachiopods, lamelli- 

 branchs, and phyllocarida. 



The contemporaneous volcanic group follows, succeeded by cal- 

 careous shales weathering olive-green, as in Backside Beck. The 

 latter are much penetrated by lamprophyres, and fossils are ill- 

 preserved, with one important exception to be noted immediately. 

 The beds do not appear to be so thick as in Backside Beck, and 

 some are probably faulted out. 



At the extreme summit of these beds, above the volcanic group 

 and immediately below the ordinary ' pencil-slate ' Ashgill Shales, 

 are calcareous beds with Phacops mucronatus and abundant 

 Cystidea. The following were found : — 



Caryocystit.es davisi M'Coy. 

 Henncosmites squamosus Forbes. 

 Echinosphcerites aurantium Forbes ? 

 Turrilepas. 



Phacops mucronatus. 

 Leptmna. 

 Orthis. 

 Conularia (?). 



This deposit may be 

 Staurocephalus Group. 



referred to as ' the mucronatus band of the 

 It is marked by the first appearance of 



