120 



objective should be ascertained and engraved upon it— if not by its maker, 

 then by some standard authority, such as has been proposed here this evening. 

 Mr. Ward also said he would call attention to the carious material exhibited 

 by Mr. Topping on one of the stands. The substance entered into the com- 

 position of a shelly rock of the Tertiary series, forming extensive elevated beds 

 in Western Iowa. He had brought some fragments with him from the United 

 States, from which Mr. Topping had prepared a few slides. The substmce 

 would be found interesting in many respects. It was found embedded in the 

 coarse cement, or matrix, which held together the constituent shells of the 

 rock, the general character of which was cretaceous; but this material would 

 be seen to be composed of minute globular grains of silex, without cement or 

 admixture of any kind. Each grain was a microscopic globe of silex, perfectly 

 transparent and free. In water they would be seen to roll about like marbles. 

 They were less than the -j^qq of an inch in diameter, and when laid out in 

 quantity, flat upon a slide, they would each show the transmitted image of any 

 suitable object held below the stage, as was the case with the facets of the eye 

 of a beetle. On breaking up the hard, granular matrix of the rock it would 

 be found to contain, mostly in a fragmentary state, the frustules of half-a- 

 dozen species of fresh-water diatoms, interesting to any who may still be 

 sceptical on that question, as proving, incontestably, the existence of very 

 ancient fossil diatoms. 



The following objects were exhibited : — 

 Diatoms and Podura Scale, with dark ground illumi- 7 M • P n W'll" 



nation ... ... ... ... ^ " * 



Injected Voluntary Muscle of Frog... ... ... Mr. A. Topping. 



AcariofBat ... ... ... ... ... Mr. J. A. Smith. 



Alcyonella stagnorum ... ... ... ... Mr. Geo. Burch. 



Acarus of Phalangium (alive), and various Insect") -^^^ Pr d F't h 



Mountings (dry) ... ... ... S 



Arrangement for Protecting High Powers when in ■) M E P,' 1 d 



use ... ... ... ... ... 5 * * 



Triceratium armatum\ , ,„ 



. ^„ i ... ... ... ... Mr. J. W. Goodinge. 



Acan of Sparrow ■' 



r J. W. Ward, of the 



Globular Silica, from America ... ... -5 Bailey Microscopical 



Members present, 73 ; Visitors, 12. 



Society, U.S.A. 



October 11th, 1872. — Conversational Meeting. 



The following objects were exhibited : — 



Insects (various) from Ceylon Mr. Hailes. 



Injected Tendon of Horse Mr. A. Topping. 



Turbot scale ... Dr. Matthews. 



Seed oi SpJioenogyne speciosa Mr, Golding. 



Section of Spinal Cord (human) Mr. Curties. 



Daphnia pulex (alive)... Mr. Martinelli. 



Male Gnat, with parasites ) 

 Exuvium of Froghopper ' 



Nostoc comm.une Mr. Ingpen. 



Galinsoga parvijlora (fruit) Mr. Jackson. 



