J. W. JT7DD ON THE SECONDARY ROCKS OP SCOTLAND. 



709 



Hattan is especially interesting, as exhibiting a last vestige of the 

 usually grandly developed Lower Lias of this area. Only a few feet 

 of Lias strata are here found cropping out from beneath the uncon- 

 formably superposed Cretaceous ; but the age of the beds is, fortu- 

 nately, placed beyond question by the discovery of the following 

 fossils — Gryphcea arcuata, Lam., Unicardium cardioides, Phill. sp., 

 Cardinia Listeri, Sow. sp., Lima pectinoides, Sow. sp., Pecten, sp., and 

 Pentacrinus, sp. The strata containing these fossils exhibit all the 

 usual characters of the Lower Lias, consisting of alternating limestones 

 and shales; they appear to rest directly upon the Poikilitic; and 

 certainly the Infralias, if present at all, must be reduced to insig- 

 nificant proportions. 



As indicating the richness of the fauna of the Lower-Lias strata 

 around the shores of Loch Aline, we may cite the following list of 

 fossils found there : — 



Vertebra of Ichthyosaurus. 

 Ammonites Bucklandi, Sow., very large 



■ multicostatus, Sow. 



Oonybeari, Sow. 



kridion, Hehl. 



— spmaries, 



spiratissimus, Quenst. 



, sp. 



Nautilus striatus, Sow. 

 Phasianella(?), sp. 

 Cardinia Listeri, Sow. sp. 

 Myaeites liasinus, Bom. 



alduinensis ? 



Pholadomya glabra, Ag. 

 Astarte dentilabrum, Eth. 

 Pinna Hartmanni, Gold/. 



Lima gigantea, Sow. s-p. \ both very large 



succinata,$cA£sp. J and abundant. 



pectinoides, Sow. sp. 



Avicula sinemuriensis, D Orb. 

 Peeten textorius, Schloth. 



Hehlii, D'Orb. 



, sp. [(rare). 



Ostrea (Terquemia) arietis, Quenst. sp. 



Ostrea, sp. 



G-rypheea arcuata, Lam., typical form 



in enormous abundance. 

 Serpula, sp. 

 Spines of Acrosalenia. 

 Pentacrinus tuberculatus, Mill. 



briareus, Mil. 



Large Fucoid (?) markings. 



At one or two points in the vicinity of Loch Aline the ordinary 

 Bucklandi -beds, which, as we have seen, are so well developed, are 

 seen to be covered by thick masses of dark micaceous shale ; and in 

 these I have detected, at more than one locality in the district, the 

 fossils which characterize the Subzone of Ammonites semicostatus. 

 The beds on this horizon, however, are nowhere well exposed in 

 good sections in the district in question; but, taken altogether, 

 the exposures of the Lower Lias in the district of Morvern are 

 without a parallel, whether we regard the clearness of the sections 

 of the strata or the variety and admirable preservation of the fossils 

 which they yield, in the whole of the Western Highlands. 



In the island of Mull, on the other hand, the sections of the Lower 

 Lias do not present much that is worthy of note. On the shores of 

 the Sound of Mull at Craignure (Auchenacroish), opposite to Ard- 

 tornish, the Lower-Lias limestones are seen on the shore, but are 

 often converted (in consequence of their proximity to igneous 

 masses) into saccharoid limestone, in which, however, the forms of 

 GhrypTum arcuata, Lam., and Lima gigantea, Sow., can sometimes be 

 distinguished. The metamorphism of the beds is found to diminish 

 as we follow the series upwards ; and the higher parts of the Buck- 



