Microscopical Examination of Two Minerals. 227 



having scattered through its mass large patches of transparent, so- 

 called, Noble Serpentine. Mr. Gr. M. Wilber, who contributed the 

 specimen, was not acquainted with the exact locality, but Prof. 

 D. S. Martin recognized it to be identical with some in his posses- 

 sion, from that portion of New York State indicated. 



Without any special preparation and examination, by means of 

 a simple lens alone, the whole mass was seen to consist of Eozoon 

 Canadense in a remarkably fine state of preservation. Subsequently 

 I cut shces from it and ground them thin enough to permit sufii- 

 cient light to pass through, so that the microscope with higher- 

 power lenses could be employed in studying it. Some specimens I 

 acted upon by means of dilute hydrogen chloride (muriatic acid), 

 and compared with very beautiful specimens of the original Eozoon 

 Canadense from Canada, and for which I am indebted to my fellow- 

 member. Dr. L. Feuchtwanger. These specimens from both locali- 

 ties, as well as illustrative plates, I exhibited, so that all might see 

 and confirm my discovery, which must be considered as one of con- 

 siderable importance, when viewed from a geological pomt of view. 

 It may be observed that the New York specimens are very much 

 finer than the Canadian ones, that is to say, they show the structure 

 of this foraminifer in a strikingly-clear manner, and this the more 

 particularly after the action of the acid. At some future time I 

 may take an opportunity of entering into a consideration of some 

 points connected with the structure and affinities of Eozoon Cana- 

 dense, for in this material thus fortunately brought to light, we have 

 extremely favourable opportunities of studying its intimate anatomy. 

 This I will have a better opportunity of doing when I receive 

 further supplies of the material, which I am endeavouring to pro- 

 cure, and which is said to occur in large quantities at the point 

 from which this was brought. 



It is well known that the presence of this fossil is considered to 

 indicate that the rocks containing it belong to the Laurentian 

 group or period, and the bringing of them over the border and down 

 thus far into New York State is of great geological importance. 

 This is the more so, as the members of the Canadian Geological 

 Survey have only lately traced these rocks down into New England, 

 as far, at least, as Salem, Massachusetts. 



The other specimen referred to me for examination by means of 

 the microscope, and chemically if found necessary, is the lump of 

 nearly white material exhibited by Mr. J. W. Ward, and thought 

 by him to be finely-pulverized mica, and said to come from a bed of 

 clay in the State of Delaware. At the time of its exhil)ition I 

 expressed my strong conviction that it consisted of the silicious 

 skeletons of Diatomacese, and my suspicions have been confirmed. 

 In fact, strange to say, it proves to be a mass from the now well- 

 known deposit existing at Six-mile Caiion, near Virginia City, in 



