354 Hughes — Geology of the Lake District 



Professor Sedgwick. I have dropped tlie word porphyry, as I have 

 not in this district found any part of them which could be so called. 

 The specimen which I saw in the Kendal Museum also, from further 

 north, seems only a grit, though certainly altered a little. I have 

 not been able to detect any fossils in these beds, unless some obscure 

 black marks which I found in the slates due west of Twisleton 

 Manor House, should turn out to be traces of Fucoids or G-raptolites. 

 Professor Harkness has, however, shown that their equivalents fur- 

 ther north are of Caradoc age, and the passage from the Coniston 

 limestone into them near Ingleton would seem to bear out this view. 



B.&. Coniston Limestone. — A dark blue, close grained, more or less 

 calcareous slate and shale, passing into a hard blue grey crystalline 

 limestone. I have nowhere got the top and bottom of this bed in 

 one section, so I can offer no estimate of its thickness ; nor am I 

 prepared to say that it is the very same bed that occurs at the 

 different places from which I have collected fossils, and not rather 

 limestone bands on slightly different horizons of the same series. 

 Fossils are abundant. Speaking generally, the same species occur 

 everj'where, though in some localities they are more numerously 

 represented than in others. Besides the localities referred to in the 

 description of the cross sections, this formation is well exposed and 

 highly fossiliferous in the upper part of Helm Gill, and above Gaw- 

 thorp near Dent ; also in Sarly Beck, north-east of Sedbergh. 



The following are some of the fossils : — 



Salt/sites catenularia. 



HelioUtes. 



Petraia oequisulcata. 



Favosites fibrosa. 



F. 2 other sp. 



Enerinites. 



Cystideans. 



A Phyllopod crustacean. 



Calymene Bhimenbachii (var brevi- 



capitata). 

 Cheirurus bimucronatus. 

 Cybele verrucosa. 

 Illcenus. 

 Lichas. 



Fhaeops conophthalmus. 

 P. sp. 



Femopkurides. 

 Atrypa marginalis. 



B.a. Strongly cleaved slates. Near Souththwaite the difference 

 between them and the slates (A.c. 3), above may be well examined — 

 the latter being less altered, and showing the direction of the bed- 

 ding better. In the upper part the altered grits like Ash-beds 

 (B.a. 2) occur, below which, bxit some way above the limestone, the 

 Flaggy Slates (B.a. 3) with packed concretions occur. In the upper 

 part of B.a. fragments of Trinucleus become tolerably abundant. 

 So also in coming down Helm Gill we have a geologically ascending 

 section, and in the beds near the bottom, and therefore highest in 

 the series, we find Trinucleus, while fossils are scarce through the 

 beds immediately below. Also in coming south-west from Sarly 



Lepimna quinqmcostata, 



L. sericea. 



L. transversalis. 



L. small sp. 



Lingula, 2 sp. ? 



Orthis Aclonies. 



0. biforata. 



0. calligramma. 



0. eleganlula. 



0. fiabellulum. 



0. porcata. 



0. vespertilio. 



0. sp. 



Strophomena depressa. 



Murchisonia ? 



Lituiies ? 



Orthoceras. 



