1820.] Geological Society. 299 



passages for vessels ; but they convey two muscles, which, from 

 their appearance and office, the author proposed to call arena- 

 tores coniecc. These muscles arise from a large retractor 

 muscle, and the side of a firm sheath, which encloses the optic 

 nerve, which retractor and its sheath are inserted into the pos- 

 terior surface of the sclerotica. They then pass through the 

 funnel-shaped mouths of the lateral foramina, as before men- 

 tioned, and are inserted tendinous into each side of the long 

 diameter of the cornea, which is ehptical. The author supposes 

 their use to be to adapt the eye of the animal for seeing both in 

 air and water. 



March 16. — An abstract of a paper, by M. Charles Dupin, 

 was read, on the Laws of the Variation of the Flexibihty of 

 Canadian Fir Timber. It has been shown by Duhamel and 

 others that the resistance of timber against bending or breaking 

 is greater at the root than at the top of the tree ; but the mathe- 

 matical law of this diminution in the strength of the tree from 

 below upwai'ds has not been ascertained. The object of the 

 author was to investigate tliis point, and with this view he insti- 

 tuted in 1816 a set of experiments on the subject in the dock- 

 yards of Dunkirk. The experiments were made upon prisms 

 50 feet long and one foot thick, and appear to have been con- 

 ducted with great care ; but the nature of the results, and the 

 mathematical reasoning founded upon them, did not admit of 

 leing detailed. 



LINN.EAN SOCIETY. 



Jan. 18. — A paper was read, by the Rev. R. Sheppard, on the 

 British Fresh Water My tili. 



Feb. 1 and 15. — The Society adjourned. 



Feb. 22. — A paper, by Dr. Leach, was read, on Four New 

 Genera of Vespertihonida). 



At this meeting also. Prof. Temminck's paper, on some Birds 

 from New Holland in the Society's jMuseum, was continued. 



March 7.— Some Remarks on the Shoveller Duck were read, 

 by Mr. Youell, of Yarmouth. 



March 2\. — Professor Temminck's paper, on the Birds from 

 New Holland, and Dr. Leach's paper, on the VespertiUonidse, 

 were concluded. 



A letter, from W.Butler, Esq. was also read, on the Manage- 

 ment of Bees. 



GEOLOGICAL SOCIETY. 



Jan. 21. — The continuation of a paper was read, " On the 

 Coal Fields adjacent to the Severn ; " by Professor Buckland 

 and Rev. W. D. Conybeare. 



From the northern apex at Tortworth where the west frontier 

 of the coal field meets its east border at an acute angle, the 

 latter is continuous with its usual character as far as Sodbury; it 

 is here, however, so low, that having been partially overrun by 



