716 



J. W. JTTDD ON THE SECONDARY ROCKS OE SCOTLAND. 



disposal. Prom Mr. Miller's and my own collections I am able to 

 give the accompanying list, which, although by no means exhaustive, 

 will suffice to prove the beds in question to be without doubt the 

 Pabba Shales. The fossils here are very numerous, but in a very 

 bad state of preservation, and often very difficult of determination. 



List of Fossils from the Pabba Shales at Tobermory. 



Eelemnites elongatus, Mill, 



acutus, Mill. 



Ammonites oxynotus, Querist. 



raricostatus, Ziet. 



densinodus, Quenst. 



Buvignieri, If Orb. 



ibex, Quenst. 



Valdani, 2?' Orb. 



Scalaria liassica, Quenst. 

 Turbo foveolatus, Ziet. 

 Pkoladoruya ambigua, Sow. 

 Unicardium cardioides, Phill. sp. 

 Lyonsia unioides, Bom. 



scottica, Wr. sp. 



Leda complanata, Phil. sp. 

 subovalis, Gold/. 



Cucullasa Miinsteri, Gold/. 

 Myoconcha oxynota, Quenst. 



scabra, Terq. et Piette. 



Area elongata. 



Mytilus hippocampus, Y. fy B. 

 Limea acuticosta, Goldf. 

 Lima punctata, Sow. 



succincta, Schloth. 



Pinna folium, Y. <$c B. 

 Plicatula spinosa, Sow. 



laevigata, D' Orb. 



Pecten sublsevis, Phill. 



priscus, Schloth. 



— < — tumidus, Ziet. 

 Gryphsea obliqua, Goldf. 



The general association of fossils at Tobermory appears to prove 

 that the horizon represented there is the base of the Pabba shales ; 

 and we have apparently an admixture of Lower- and Middle-Lias 

 species. This is the only locality on the west coast of Scotland at 

 which the peculiar fossils of the Zone of Ammonites oxynotus have 

 been found ; and here they occur mingled with others that belong- 

 to higher horizons. On the east coast of Scotland, as we have already 

 shown, the Zone of Am. oxynotus is very distinct and well developed. 



At several points about Loch Aline and Ardtornish the Middle 

 Lias beds are certainly present, but, being covered with vegetation, 

 exhibit no section. 



On the opposite shores of the Sound of Mull the dark black shales 

 of the Pabba Series make their appearance below Duart House, but 

 are here, as a rule, remarkably unfossiliferous, though of considerable 

 thickness. The overlying Scalpa beds are also present, but exhibit 

 very different mineral characters from those by which they are distin- 

 guished in their northern exposures. In Mull the Scalpa beds are 

 represented by greenish sandstones, with but little calcareous matter, 

 and very poor in fossils. The abundance of carbonaceous matter in 

 some of these beds, coupled with the presence of false-bedding, ripple- 

 markings, worm-tracts, and fucoid impressions, points to the con- 

 clusion that they originated in water of considerably less depth than 

 their northern equivalents. 



Some greatly altered rocks at Loch Spelve, on the south-east of Mull, 

 have yielded me Pecten sublcevis, Phill., and one or two other Middle- 

 Lias fossils ; and it is probable that the same formation is represented 

 among the intensely altered strata of the south coast of this island. 



At Carsaig strata in a less altered condition, fortunately, make their 

 appearance. Above the Lower-Lias strata of this locality, we find 



