PRESIDENT S ADDRESS ON THE DEATH OF PROF. J. R. KLMAHAN, M.D. 35 



a new idea in natural history, and to mould it into its true scientific 

 form ; and, though he had not made geology his study, his keen per- 

 ception guided him almost intuitively to the comprehension of many of 

 its subtle truths, and he entered the field, not only as an expounder of 

 some of its most interesting problems, but as an original discoverer. In 

 the first instance he determined the true rank in the natural history 

 scale of those obscure fossils called Oldhamia, which so rarely are met 

 with in the Irish Cambrian rocks ; and, secondly, he proved that these 

 were not the only organisms which those rocks contained. In the 

 "Journal of the Geological Society of Dublin" for 1 844, Professor Oldham 

 published an account of certain obscure markings in the Cambrian rocks 

 of Bray Head, which he supposed to be zoophytic, " and not referrible 

 to any known genera." In the year 1848 Professor E. Forbes took up 

 this interesting subject, and again brought it before the notice of the 

 Society; he pronounced the fossil to be allied to the " Ascidian Zoo- 

 phytes," or rather " compound tunicated Mollusca," and he named it 

 " Oldhamia," subdividing it into 0. antiqua and 0. radiata. Dr. Ki- 

 nahan, not satisfied with the scientific accuracy of this definition, took 

 up the subject with his accustomed zeal ; and for two years he perse ver- 

 ingly devoted every spare moment of his time to its elucidation, ac- 

 tuated by the desire to arrive at the most truthful conclusions as to the 

 zoophytic life, the climatal and other conditions prevalent during the 

 formation of some of the oldest of our stratified rocks, and which up to 

 the years 1843-4 had generally been considered as azoic. In April, 

 1855, Dr. Kinahan, having discovered the object of his search in the 

 Cambrian rocks, at Greystones, and also at Howth, brought a memoir 

 on the genus Oldhamia before the Royal Irish Academy, and they pub- 

 lished it in their "Transactions." His concluding remarks on this subject 

 are as follows : — " There are, I am aware, a few specimens of creeping 

 Polj'zoa which have a mode of growth somewhat resembling 0. radiata ; 

 but it appears to me that 0. antiqua must have been a Sertularian, and 

 it is, therefore, more probable that Oldhamia radiata was so also. 

 There remains now but to sum up in brief the points established in the 

 review of this genus, which are — In the schist rocks of the Irish Cam- 

 brian, beds occur of considerable thickness, traceable continuously for 

 many hundreds of yards, which are composed almost entirely of the po- 

 lypidoms of an extinct Sertularian, which occurs in connexion with other 

 extinct aquatic types, such as Annellids, Mollusca, and Asteroid Polyps. 

 That these fossils, judging from the almost absolute identity of one of 

 them with the polypidom of a living Sertularian type, are more probably 

 the polypidoms of extinct Hydrozoa than Coenaecia of Polyzoa ; and 

 that, judging from their state of preservation, their mode of occurrence 

 in enormous masses, and the nature of the rocks in which they occur, 

 they were originally the inhabitants of a comparatively still sea, and 

 deposited by a gentle current on the shores of a shallow sandy bay." — 

 "Transactions of the Royal Irish Academy," vol. xiii., p. 561. 



As the search after one truth, if patiently and accurately followed, 

 will ever be certain to lead to the discovery of others, Dr. Kinahan 



