Tol. 68.'] SUCCESSION IN THE NOETH-AVEST OF ENGLAND. 473 



Fauna. 



Alveolites capillaris (Phill.)- ' Producius cormgato-hcmispheriGUS 



Alveolites ethtridgi Thomson. 

 Lithostrotion irregulare (Phill.). 

 Lithostrotion (Nemato'phyllum) minus 



M'Goy. 

 Syriiigopora gcniculata Phill. 

 Hyringo'pora sp. 



Athyris cf. expansa (Phill.). 

 Chonetes papilionacea Phill. 



V a ugh an. 



Productus cLjimhriatus Sby. 

 Productus cf. striatus Fischer. 

 Seminula ambigua (Sby ). 



Bellerophoib sp. 

 Murchisoina sp. 



StrapciTollus sp. 



Pscphodus magmts M'Coy, 



Geographical distribution. ■ — Present in all districts 

 throughout the North- Western Province, 



(l/8) The Bryozoa Eand. 



This band forms a very constant horizon everywhere in the 

 type districts, and is also well developed along the Pennine 

 Escarpment. It has not been met with in the Western Districts, 

 where it appears to be merged in the upper portion of the Neinato- 

 jjhyllum-minus sub-zone. The western boundary of the area in 

 which the Bryozoa Band was deposited lay roughly somewhere 

 parallel to a line joining Sedbergh and Kidsty Pike. East of this 

 line the Bryozoa Band is typically developed ; while west thereof it 

 is absent, and we find the Chonetes-])ainlionacea Beds instead. The 

 difference was evidently due to the somewhat deeper and clearer 

 character of the sea to the west of this line. 



Lithology. — The band varies considerably in lithological 

 character from place to place. It includes some 30 or 40 feet of 

 rock, and forms a passage-bed between the Nematopliylluin-minus 

 Sub-zone and the Lower JDibunojjJiyUiim Sub-zone. The band repre- 

 sents a change in the character of the deposits, due probably to a 

 slightly increased rate of submergence which changed the direction 

 of the currents. It is alternately a shaly limestone, a compact 

 porcellanous cementstone, and a hard yellow fragmental limestone. 

 In the Pennine District it becomes more crystalline and somewhat 

 bituminous. 



Eauna. — The band is not always fossiliferous throughout. It 

 includes one or more layers crowded with fossils, notably bryozoa, 

 together with Spiriferina laminosa and AvicvJo^jecten dwnontianus. 

 In the Shap District the band abounds locally with ]S;atico]Dsis 

 plicisiria, Capulids and other gastropods; while in places, especially 

 in the Westmorland Pennines, it is characterized by the interesting 

 bryozoan Stenojwra compacta. The porcellanous layers often contain 

 numerous minute spherical bodies, which appear to be identical 

 with the form described by Williamson from the Carboniferous 

 Limestone near Mold under the name of Calcisjpliera. These bodies 

 are now preserved in calcite, but it is impossible to determine 

 whether this was their original condition, or whether they were 

 originally composed of chitin or even silica. Mr. E. C. McLean, 



