40 DUBLIN UNIVERSITY 



" Presented, with an Address, by the President and Members of the 

 Dublin University Zoological and Botanical Association, to Captain Sir 

 F. Leopold M'Clintock, R. N., LL. D., Dub., Friday, 16th March, 1860." 



The whole will be enclosed in a handsome ship's bookcase, made of 

 oak, varnished. 



The names of Subscribers (many in autograph, the others neatly en- 

 grossed in fac-simile) were affixed to the sheet of vellum which contained 

 the Address. 



The President then declared the meeting to be adjourned. 



FRIDAY EVENING, MARCH 16, 1860. 



Peofessob W. H. Haevey, M. D., M. R. I. A., F. L. S., F. R. S., Presi- 

 dent, in the Chair. 



The Minutes of last Meeting were approved of, and signed by the Pre- 

 sident. 



W. H. Baily, F. G. S., read the following paper: — 



ON FOSSIL CHITONTDJ2, AND THEIE DISTEIBUTION IN GEOLOGICAL TIME. 



Amongst all the shell-bearing families of the class Mollusca, which in- 

 cludes so many varieties of form, that of the Chitonidae presents the 

 most anomalous characters ; its shell being composed of eight distinct 

 plates, overlapping each other, and inserted into a leathery substance, 

 which forms an expanded margin round the animal, being either smooth, 

 imbricated, or spiny. 



The genus Chiton was founded byLinnoeusin 1758, and included in 

 his division multivalves. The few living examples which were then 

 known, have now increased to more than 200 species. The fossil ex- 

 amples of this genus were not noticed until some time afterwards ; they 

 are now represented in nearly all the principal groups of strata, and 

 amount to upward of forty species. 



The following abstract, in chronological order, of the history of the 

 discovery of fossil Chitons in the various strata, with descriptions of two 

 new species from the Upper Silurian of Dudley, I have translated from 

 an article, by Professor L. De Koninck, in the " Bulletins de PAcademie 

 Royale des Sciences, de Belgique, 26 m * annee, 2 m *, ser. t. 3, 1857." 



