G. H. Kinahan — Irish Met amorphic Rocks. 7 



number of parallel rods in close apposition, but highly curved in 

 the former ; the anterior edge in both being oblique, the extremities 

 of the rods terminate at the border, constituting with its dentated 

 edge the offensive part of the spine. 



Without attempting more on the present occasion than to point 

 out the intei-esting analogy between the Australian fossil and the 

 American genus Edestus, it seems, nevertheless, of the greatest 

 interest to call attention to the probable nature of this organism 

 and its geological age. 



So lately as June 6th, 1883, Mr. W. H. Hudleston, F.R.S., F.G.S., 

 communicated a paper to the Geological Society of London, " On a 

 Collection of Fossils and of Rock-Specimens from West Australia, 

 north of the Gascoyne River," since published in the Quart. Journ. 

 Geol. Soc. vol. xxxix. pp. 582-595, pi. xxiii. 



In this paper Mr. Hudleston mentions an earlier paper by Mr. 

 F. T. Gregory in 1861, and a map and sections presented to the 

 Society in 1847. " The paper and sections by Mr. Gregory must 

 be regarded (says Mr. Hudleston) as having laid the foundation of 

 Western Australian Geology south of the parallel of the Gascoyne 

 river." " Mr. Forrest, the Colonial Surveyor, appears to have 

 discovered a range, or more properly a sort of continuous out- 

 crop trending N.N.W. for nearly 150 miles, which has yielded an 

 interesting suite of Carboniferous fossils." A list of about 32 species 

 is given by Mr. Hudleston, namely, 5 Corals, 2 Echinodermata, 4 

 Polyzoa, 8 Brachiopoda, and 2 Lamellibranchiata. It is not with- 

 out interest in connection with the present discovery of a Fish-spine 

 in this region closely related to the American Edestus of Leidy, that 

 two species of Evactinopora are described, one of which is said to be 

 similar to Meek and Worthen's Evactinopora grandis and is also, 

 like Edestus, from the Carboniferous of Illinois (see Hudleston, op. cit.). 



I have been requested to append the discoverer's name to this 

 fossil, and as I am unwilling, in the present state of our knowledge, 

 to make a new genus for its reception, I propose to name it Edestus 

 Davisii. 



EXPLANATION OF PLATE I. 

 Fig. la. Pectoral fin ? spine of Edestus Davisii, H. Woodw. (nat. size), from the 



Carboniferous Series of the Gascoyne District, Western Australia. 

 lb. Conjectural outline section of spine. 



II. — Irish Metamorphic Rocks. 



By G. H. Kinahan, M.R.I.A., etc. 



Read at British Association, Aberdeen, 1885. 



THE meeting of the British Association in Montreal gave different 

 Irish geologists facilities for examining the Archaean rocks of 

 Canada and the States, while since then they and also American 

 geologists have had opportunities for studying the Irish Metamorphic 

 rocks ; it may therefore be allowable to give an epitome of our 

 knowledge in regard to the latter. 



In ten localities in Ireland are found metamorphic rocks moi'e or 

 less similar to those of America; these localities may be classified as 



