proceedings: biological society 519 



tourmaline, specularite, argentite, bromyrite, and a gold telluride. Some 

 of the gold is coarse, which fact suggests that these veins probably 

 represent an important source of the rich placers mined in neighboring 

 Spring Valley and American Canyon. 



From the presence of minerals of deep-seated origin, the replacement 

 character of the deposits, and hydrothermal alteration of the rocks, 

 the Rochester deposits seem to have been formed at relatively high 

 temperatures and at considerable depth. Their origin is referred to 

 magmatic solutions and gases emanating from post-Jurassic granite, 

 which as a batholithic mass intrudes the rocks on the north and is 

 believed to extend beneath the district. The deposits therefore are 

 probably of early Cretaceous age. 



From the deep-seated character of the deposits and their close asso- 

 ciation with the major geologic structures which are very persistent, 

 it is believed that some of the deposits may extend to considerable 

 depth. 



W. C. Alden: The Iowan stage of glaciation — a review of the evidence 

 based upon field studies in 1914 an d 1915, by the United States and Iowa 

 Geological Surveys. For resume of the facts presented in this paper see 

 Bull. Geol. Soc. Amer., 27: 117-119. 1916. 



Carroll H. Wegemann, Secretary. 



THE BIOLOGICAL SOCIETY OF WASHINGTON 



The 557th regular meeting was held at the Cosmos Club on May 20, 

 1916; called to order by President Hay at 8 p.m.; 30 persons present. 



On recommendation of the Council, James L. Peters was elected 

 to active membership. 



The President announced that the Council of the Society had voted 

 to adopt the custom of the medical and of many other scientific societies 

 of allowing members to speak but once during the discussion of a paper 

 and of asking the original speaker to answer all questions at the end 

 of the discussion and to close the same. 



Under the heading of Brief notes and exhibition of specimens, Dr. 

 Howard E. Ames referred again to the dorsally placed mammae of 

 the coypu (Myocastor coypu) and exhibited photographs of a female 

 coypu in the collection of the Philadelphia Zoological Society show- 

 ing the mammae so placed. 



The first paper of the Regular program was by A. T. Speare: Some 

 fungi that kill insects. Mr. Speare spoke briefly of certain experiments 

 that were conducted in Europe about 1885, in which the "green mus- 

 cardine" fungus was used in a practical way to combat the cockchafer 

 of wheat. Reference was also made to similar work that has recently 

 been conducted in Florida, and Trinidad, B. W. I. The writer spoke 

 also of the present status of the chinch bug disease and of the brown 

 tailed moth disease. In regard to the latter he spoke in detail of the 

 methods employed in spreading this disease in the field. At the end 

 of the paper he exhibited slides illustrating various types of entomog- 



