1867.] 303 [Greenleaf. 



very much inferior to the instruments now in the hands of 

 our microscopists. Mr. Stodder exhibited, in comiection with 

 this, the one-tenth objective Avith immersion front, whicli he 

 used in resolving the markings above described. 



Mr. Ti. C. Greenleaf placed on the table an immersion lens 

 from Ilartnack of Paris, one-fifteenth focus ; also one from 

 Tolles, of the Boston Optical Works, one-fifth focal distance. 



These objectives Mr. Greenleaf said he had used with 

 great satisfaction, being .able with them to resolve some of 

 the most diflicult test objects, such as the Cuban Amphi- 

 pleura^ Amici test, or small specimens of Navlcula rhom- 

 boides, with more ease and certainty than he had ever 

 resolved them witli any dry lens. The one-fifth lens, made 

 by Tolles, works with great distinctness, bearing the higher 

 eye pieces admirably. 



The Cuban AmpMpleura was shown by Mr. Greenleaf to 

 illustrate the working jjower of these various objectives. 



Mr. C. Stodder exhibited a student's microscope stand from 

 the Boston Optical Works. This instrument will be pro- 

 vided with one eye j^iece and two objectives, an inch and 

 quarter inch. The tube has coarse and fine adjustment. 

 An independent stand is made for the mirror, so that it 

 can be used for illuminating opaque objects. The whole in- 

 strument will be of the best workmanship, and produced at 

 the lowest possible cost. 



October 16, 1867. 

 The President in the chair. Forty-four members present. 



The President, referring to the record of the previous 

 meeting, stated that he had made a further examination of 

 the bones found at Goose Island, and had had an opi)ortunity 

 of comparing them with Owen's plates of the Great Auk. 

 The humerus of the bird proved to be identical with the fig- 

 ures by Owen, leaving no doubt of the character of the 

 remains. 



