Tute — Natural Pits near Ripon, 179 



about every 10 feet of rock. The rock was much harder as the 

 shaft descended, and alternated red and white. The rock is not 

 laid in horizontal layers, but is what well-sinkers call Eddy-Bock ; 

 and not all inclining one way, but crossing one another with great 

 irregularity, and at various angles of descent." 



Three of these pits have been formed in the memory of persons 

 now living. The one marked a fell in about six or seven years ago. 

 A clergyman, who happened to be near at the time, told me that he 

 was standing by the river side with some boys watching two men, 

 who were fishing, when they heard a noise like thunder ; and looking 

 round in the direction of the noise, they saw a mass of earth and 

 stones rising into the air, and then falling down again. One of the 

 men went near, and found that the rock had fallen in, and a pit had 

 been formed about 30 feet in depth, at the bottom of which there 

 was a quantity of water in a state of ebullition. The water con- 

 tinued in this agitated state during the following day, and afterwards 

 gradually sunk. At present the pit is dry, and partially filled up 

 by the falling in of one side. 



Another pit, 6, fell in about twenty-two years ago with a con- 

 siderable noise, alarming the inmates of a neighbouring house, 

 from which it is only separated by a road, but otherwise doing no 

 harm. It is crater-like, having occurred beneath the gravel, and is 

 now planted as an orchard. The pit marked c, mentioned above, 

 fell in about forty years ago. It contains water, but in dry seasons 

 this is nearly all drained away, and the rock is laid bare at the 

 bottom. 



These pits are also of frequent occurrence in the parish of Hutton 

 Conyers ; there are several in Sharrow, and one in Bishop Monkton, 

 three miles south of Eipon, which was formed between thirty and 

 forty years ago, near the Old HaU. Some men had been engaged 

 in making a stack, and had left it for some purpose, when suddenly 

 the ground gave way beneath the stack, and it disappeared. The 

 place still exists, a receptacle for rubbish. 



Perhaps some of the readers of the Geological Magazine will 

 be able throw a little light upon the manner in which these singular 

 pits have been probably formed. 



JiTOTZCES oip :IyE:E3^0Iz^s. 



On Leskia Mibabilis (Gray). By Prof. S. Loven. 



Comnmnicated by Dr. Christian Liitken, Assistant Zoologist in the Museum of 

 the University, Copenhagen. 



THIS little paper, inserted in the "Proceedings of the Eoyal 

 Swedish Academy" for 1867, well deserves the attention of 

 palseontologists, though its principal aim is to re-describe a little- 

 known recent Sea-Urchin from the Eastern Seas, because this animal 

 throws a peculiar light on certain important points in the morphology 

 of Cystidea. It is, moreover, distinguished by all the ingenuity. 



