100 Proceeclhvjs of the Royal Physical Society. 



14. Halidrys siliquosa, permanent variety. — There is so 

 distinct a line of demarcation between this 

 slender feathery variety and the typical form of 

 Halidrys siliquosa, that our British authorities 

 who have examined the specimens consider it 

 ought to rank as a sub-species. It has hitherto 

 been found only at Broxmouth, near Dunbar, in 

 pools near low water, associated with typical 

 Halidrys siliquosa, but never passing into it. 



XI. An Addition to the Fish Fauna of the Oil Shales of 

 Edinlurghshire. By John Gibson, Esq. 



(Read 18tli January 1882.) 



The extensive scale on which the bituminous shales of 

 Edinburgh and Linlithgow shires have of late years been 

 worked in connection with the parafifm industry, has afforded 

 the paleontologist an opportunity of becoming acquainted 

 with the life of the period to which they belong. The oil 

 shale itself is, as a rule, singularly destitute of fossils. As- 

 sociated with it, however, is a non-bituminous shale known 

 to the miners as " blaes," and which is more or less thickly 

 studded with ironstone balls or nodules. Industrially worth- 

 less, this material is scientifically valuable on account of the 

 fossils embedded in it. Plants are specially abundant in 

 the shale, but, so far as my experience goes, the fish remains 

 are confined to the ironstone nodules. There is little doubt, 

 however, that they occur in the shale as well; only having 

 once found fish remains in the nodules, the collector is apt 

 to confine his attention to these to the neglect of the other. 

 Recently I found this to be the case with another non- 

 bituminous nodular shale, namely, that occurring along the 

 shore at Wardie. Fish remains have been collected from 

 that locality persistently for half a century, but in all cases, 

 so far as I have been able to learn, they have been obtained 

 only from the ironstone nodules, the shale having yielded 

 nothing ichthyic beyond a few detached scales. When col- 

 lecting recently at Newhaven, for want of nodules to operate 

 upon, I took to splitting detached water-worn pieces of the 



