Wells.] 530 [Apr. 4, 



daytime. He acquired a large and valuable collection of micro- 

 scopical apparatus and paid much attention to the construction and 

 use of high power objectives. It was largely due to his liberality 

 and encouragement that the late Robert B. Tolles was enabled to 

 take up his residence in Boston and progressively improve the 

 construction of his objectives until his reputation as a skilful op- 

 tician became world-wide. 



Mr. Greenleaf understood thoroughly the theory and construction 

 of the microscope and his skill in its manipulation was excellent. 

 For his particular study he selected a group of algae known as the 

 Diatomaceaa, and was one of the earliest students of this family in 

 the country. He made a large collection of them and of the liter- 

 ature descriptive of their varied and beautiful forms. About 1860 

 or 1861 he found a new and finely ornamented species which he 

 named Stauroneis Stodderii in honor of his friend the late Mr. 

 Charles Stockier, a member of this Society for many years, and an 

 authority on the Diatomaceae. This species is described in a paper 

 " On Extreme and Exceptional Varieties of Diatoms, etc.," by 

 F. W. Lewis, M.D., published in the Proceedings of the Academy 

 of Natural Sciences of Philadelphia, January, 1865. 



In 1869, Mr. Greenleaf made a communication to this Society 

 on the subject of "The Double Plate of Aulacodiscus Oregonus." 

 It is unfortunate that so careful an observer did not favor us with 

 more of the results of his work. 



Mr. Greenleaf became a member of this Society on December 5, 

 1860, and gave freely of his time and money to its purposes, espe- 

 cially in the department of microscopy, during the rest of his life. 

 In 1870 he was chosen a member of the committee on microscope 7 , 

 which made him a member of the Council. In 1871 he was elected 

 second Vice President and continued to hold that office until 1874. 



In 1877 Mr. Greenleaf with Dr. A. D. Sinclair presented to the 

 Society 477 slides of microscopical objects prepared by Mr. Wil- 

 liam Glen, a valuable and interesting addition to the collection of 

 slides. Mr. Greenleaf further manifested his interest in this So- 

 ciety by bequeathing to it his microscopical library containing sev- 

 eral rare and valuable works, his apparatus and collection of slides, 

 consisting of two Tolles' stands, one large and one small, nine 

 objectives, and a variety of accessory apparatus, also about 2150 

 slides of which about one-half are diatoms and the rest anatomical, 

 botanical, entomological and miscellaneous. 



