1888.] MICROSCOPICAL JOURNAL. 19 



Pioche, Nev., and the other from a deposit near the Edge Hill Vineyard, in Napa 

 county. Mr. Riedy and Dr. Riehl reported upon a previous donation from Mr. Irelan 

 from Shasta county, that the earth was rich in diatoms, but contained only a few of 

 the commoner forms. 



There was a discussion on the subject of admitting microscopical instruments free 

 of duty, whether for societies or for individuals. The wisdom of such a policy was 

 urged, because it would aid the scientific investigator, while the present tariff continu- 

 ally hampers him. The following committee to memorialize Congress was appointed : — 

 Henry C. Hyde, Dr. S. M. Mouser, Dr. J. M. Selfridge. 



Dr. Riehl exhibited Peterson's freezing microtome, which was favorably received. 

 Dr. Ferrer spoke upon cell growth. Dr. H. W. Harkness called attention to the state- 

 ment of the United States Mycologist, that Peronospora viticola was not found in this 

 State, and said that he had found it as early as 1872. An account of its occurrence 

 was published by the California Academy of Sciences in June, 1887. 



American Society of Microscopists. 



The list of officers for 1888, which was printed on page 208 of last year's Journal, 

 being somewhat faulty, this occasion is taken to publish a corrected list, as follows : — 

 President, Prof. D. S. Kellicott, of Buffalo, N. Y.; ist Vice-President, Prof. T. B. Stowell, 

 of Cortlandt, N. Y. ; 2d Vice-President, Dr. H. T. Detmers, of Columbus, Ohio; Sec- 

 retary, Prof. T. J. Burrill, of Champaign, 111. ; Treasurer, Dr. S. M. Mosgrove, of Urbana, 

 Ohio ; Executive Committee, C. C. Mellor, of Pittsburgh, Pa ; Dr. H. D. Kendall, of 

 Grand Rapids, Mich.; Dr. R. J. Nunn, of Savannah, Ga. 



NOTICES OF BOOKS. 



Fresh-water Sponges: — A Mo7iograpJi. By Edward Potts. Philadelphia, Penn. 

 Academy of Natural Sciences. 1887. pp. 157-279 ; pis. v, vi, viii, ix, x, xi, xii. 



The author of this Monograph has laid American zoologists under obligation by the 

 preparation of an interesting and very extensive study of fresh-water sponges. His 

 purpose appears in the following words from his preface : — ' My design has been pri- 

 marily to describe those genera and species, mostly North American, that have been 

 discovered since the dale of Mr. Carter's publication (1881) ; next to detail the results 

 of a somewhat extended examination into the character and variations in North America 

 of those species that have long been familiarly known in Europe, and thirdly to make 

 it valuable for reference as a monograph by adding brief technical descriptions of all 

 other "good species." 



' A further purpose, and one that I hold much at heart, is the desire to revive among 

 scientists and lovers of nature an appreciation of the apparently almost forgotten fact 

 of the existence of sponges in our fresh water ; to show them that they are easily found 

 and collected ; that they are deeply interesting as living objects of study, microscopic 

 and otherwise ; and that by simple processes their typical parts may readily be pre- 

 pared for classification, and the permanent preservation of their various singular forms.' 



We deem it the reviewer's duty to discover the purpose of a writer and to report how 

 far, in his judgment, the writer has succeeded in executing it. In this case the claims 

 of the writer are amply met in every particular. Every reader, by the aid of the nu- 

 merous synoptic keys and fuller specific descriptions, can identify any sponge he may 

 meet, and will learn many facts of general biologic interest in addition to merely dis- 

 covering the name of the specimen. The illustrations deserve grateful acknowledg- 

 ment for their maker, Miss S. G. Foulke, of Philadelphia. We do not know whether 

 a supply of the Monograph for general distribution has been provided by the Academy, 

 or upon what terms they could be obtained, but we think the work deserves to find its 

 way into the hands of all naturalists. 



Sixth Annual Report of the United States Geological Survey. By J. W. Powell. 

 Washington, D. C. 1885. 

 This number of an admirable series contains, in addition to the detailed report of the 

 work done by the various survey parties, five extended papers of very general geo- 

 logic interest. These are: — i. Mount Taylor and the Z6ni Plateau, by Captain C. E. 



