Oct. 4, 1921 proceedings : philcsophical society 395 



ENTOMOLOGY. — The Dipterous genus Dolichopus Latreille in North 

 America. M. C. Van Duzee, F. R. Cole and J. M. Aldrich. Proc. 

 U. S. Nat. Mus., Bull. 116. Pp. 304, pis. 16. 1921. 



This paper is a revision of the North American species of the genus Doli- 

 chopus. It is divided into three parts. The introduction by J. M. Aldrich 

 gives a historical account of the genus and notes on the habits of certain 

 species. The second part, entitled "Classification," by M. G. Van Duzee, 

 occupies the largest portion of the work. In it 219 North American species, 

 many of which are new, are described, the location of the types is stated 

 and there is an account of material before the author. This section is in- 

 troduced with a synoptic table of the species. The males are treated first 

 and are divided into nine groups. The females are also tabulated, but do 

 not fall into the same groupings as do the males. This is due to the unusual 

 and peculiar secondary sexual characters of the males. The third part 

 is by F. R. Cole and consists of considerably more than 217 figures illustrat- 

 ing various characters of the species treated. Each species is assigned a 

 number and when two or more figures are given for the same species they 

 are given subletters of the species numbered. 



This division of the paper in three parts makes it appear that the new 

 species are to be accredited to Mr. M. C. Van Duzee and no statement to 

 the contrary is definitely made, but in the introduction it is implied that 

 new forms should be accredited to the three authors. The present writer 

 understands that such is the intention of the authors of this important and 

 comprehensive work. S. A. Rohwer. 



ETHNOLOGY. — The Owl sacred pack of the Fox Indians. Truman Mich- 

 ELSON. Bur. Amer. Ethnology, Bull. 72. Pp. 83, pis. 4. 

 The greater part of this bulletin consists of a text in the language of the 

 Fox Indians and a translation of the same setting forth the ritual connected 

 with it, its history, and the benefits supposed to follow upon the performance 

 of the ceremonies. Some linguistic notes on the text are appended and a list 

 of stems fills the 12 concluding pages. It contains contributions to the study 

 of Indian linguistics, sociology, and religion. John R. Swanton 



PROCEEDINGS OF THE ACADEMY AND AFFILIATED 



SOCIETIES 



PHILOSOPHICAL SOCIETY 



851st meeting 



The 85 1st meeting of the Philosophical Society of Washington was held 

 in the Assembly Hall of the Cosmos Club, May 7, 1921. It was called to 

 order by President Faris with 30 persons present. 



The first paper, on The self contained base range finder and its errors, was 

 presented by Mr. I. C. Gardner (by invitation) and was illustrated. 



Tlie self-contained base range finder is probably the most interesting and 

 highly developed optical instrument employed in warfare. The range is 

 determined by triangulation with the base of the triangle actually contained 

 within the instrument. It follows that the angle of parallax which is measured 

 is extremely small and must be measured with great accuracy. For example, 

 with a one-meter instrument at a range of 5000 meters the angle is approxi- 

 mately 40 seconds. The error of measurement for this angle must be less 



