j9o8. The British Association in Dublin. 239 



worm, and are simpler in structure than those of an}^ other Lumbriculid. 

 This species thus forms an interesting link between the normal lyumbri- 

 culid type and the aberrant genus Stylodrilus. The relations of the 

 dorsal and ventral vessels to the intestinal blood-sinus are also in- 

 vestigated, and shown to differ considerably from the condition t_vpical 

 of the Oligfochaeta. 



SECTION E. — GEOGRAPHY. 

 IRELAND— HER COASTS AND RIVERS. 



BY RKV, W. SPOTSWOOD GRREN, CB. 



This paper described the succession of events in the geographical 

 history of Ireland from the time that the river valleys were being 

 sculptured and the present configuration of the country determined 

 through the great Arctic and forest periods to the coming of man into 

 the island, the evolution and admixture of races, and finally dwelt upon 

 the beauty spots with which Ireland abounded, and which the author 

 hoped that many M^ho had come to the British Association might go and 

 see for themselves. 



MITCHELSTOWX CAVE. 



BY C. A, HII.L, M.A., M.B. 



Mitchelstown Ct-ve, the largest yet discovered in the British Isles, is 

 situated in County Tipperary, in the valley of the Blackwater. There 

 are actually two separate and distinct caves. The existence of one, the 

 " old" cave, is now forgotten, though this cave was known and exhibited 

 in 1777. The "new" cave, first discovered in 1S33, is now the only one 

 shown to visitors. It was first described by Dr. Apjohu, of Dublin, who 

 partially explored and surveyed it in 1834, and published a map, which 

 has been the basis of all others up to the present time. It was further 

 explored by M. Martel, of Paris, in 1895, and described by him, and was 

 al.so visited by Dr. Lyster Jameson, of Dublin, who described the cave 

 fauna found therein. Very little is known of the full extent of the caves 

 even at the present day, and no reliable plan or map exists.'' The cave 

 was visited in 1905 by the author, who took many photographs, now 

 shown for the first time, and also explored portions hitherto unvisited. 

 The cave was found to be of much greater extent and complexity than 

 was previously imagined. 



There is great need for systematic exploration and surveying, as the 

 existing plan of the "new" cave has been found inaccurate and mis- 

 leading, and practically nothing is known of the "old" cave. Geologi- 

 cally the " new " cave is of great antiquity, as evinced by the enormous 



' The cave has been since thoroughl}' explored and mapped by Dr. 

 Hill, Dr. A. Rule, H. Brodrick, and R. \^., Praeger. An account will 

 shortly be published in the Irish Naturalist, 



