172 PROCEEDINGS OP THE SOCIETY. ^ 



in the Silurian and Carboniferous strata, and appeared as small round 

 or curved dots, each consisting of a single tooth. They were formed 

 of carbonate of lime. A great deal of discussion had arisen con- 

 cerning them, and they had been thought by some to belong to fishes, 

 but owing to the great age of the rocks in which they occurred this 

 had been disputed, though he thought it possible that it might yet 

 turn out that they did. Professor Owen had thought that they might 

 belong to Annelides or Crustaceans, but the discovery of the real 

 Annelide jaws showed that they did not belong to that class. In size 

 they varied from ^ to ^^^ in., the jaws of the Annelides ranging from 

 ^ to ^V i^-* 



Mr. Gulliver's paper, " On the Classificatory Significance of 

 Eaphides in Hydrangea" was read by the President. (see p. 44). 



Professor Martin Duncan's paper, " On a part of the Life-cycle 

 of Clatlirocystis ceruginosa," was read by Mr. Stewart (see p. 17). 



The Rev. W. H. Dallinger's paper, " On a Series of Experiments 

 made to determine the Thermal Death-point of known Monad Germs 

 when the Heat is endured in a Fluid," was read by Mr. Crisp (see 

 p. 1). The figures in illustration of the apparatus used were drawn 

 on the board by Mr. Stewart. 



Dr. Matthews thought that the investigations would be of im- 

 portance in regard to the destruction of such parasites as Trichince and 

 others. They were at present not at all aware at what point the life 

 of their germs was destroyed. 



Mr. Stewart said that strong evidence would soon be placed before 

 the public to show that TricJiince would survive conditions which 

 it had not previously been thought possible that they could do ; for 

 instance, they had been detected alive after two months' burial of the 

 flesh in which they were found. 



Mr. Teasdale's paper, " On a simple Eevolving Object-holder," 

 was read by Mr. Crisp (see p. 45), the figures in illustration being 

 drawn upon the board by Mr. Stewart. 



Mr. Beck said that he had lately been surprised at the things 

 brought out as new which were really very old. and it seemed to him 

 not out of place to mention that the system of showing objects on a 

 disk like that now described was quite an old one, as in the Exhibition 

 of 1851 some opaque injections by Mr. Eainey were shown on that 

 plan, and the method was illustrated in Professor Qnekett's book.f 

 A modification of it was also made by his brother, the late Mr. Richard 

 Beck, which was exhibited by Mr. Crisp that evening. The Micro- 

 scope on the table | was also a modification of the plan devised by 



* See also ' Journal,' vol. ii. (1879) p. 884. 



t ' A Practical Treatise on the Microscope,' 3ril ed., London, 1855, p. 538. 



X See ante, p. 144. 



