DEC. 4, 1921 proceedings: philosophical society 497 



United States about 1890. Since that time it has spread into Maine, central 

 New York, Pennsylvania, West Virginia, and southeastern Virginia, where 

 it now breeds. It has wandered also to Ohio, Alabama, and Georgia, and 

 probably will continue to spread into suitable areas in the eastern United 

 States. The well-known BoboHnk {Dolichonyx oryzivorus), breeding in 

 North America, migrates to winter in Bolivia and Argentina. Tables of 

 dates of its spring and fall migration are here given. H. C. O. 



ORNITHOLOGY. — A synopsis of the races of the Guiana flycatcher, Myiarchus 

 ferox (Gmelin). H. C. Oberholser. Proc. Indiana Acad. Sci. 1918: 

 304-308. 1920. 

 Eight subspecies of this bird are here recognized, one of which has not 



heretofore been regarded as distinct. H. C. O. 



ORNITHOLOGY. — -Description of a new Otocoris from California. H. 

 C. Oberholser. Condor 22: 34-35. 1920. 



The breeding horned lark of the northern Sierra Nevada in California is 

 here named Octocoris alpestris sierrae. H. C. O. 



ORNITHOLOGY. — Fifth annual list of proposed changes in the A. 0. U. 



check-list of North American birds. H. C. Oberholser. Auk 37: 274- 



285. 1920. 

 This list includes the changes in nomenclature and status of North American 

 birds proposed during the calendar year 1919. It comprises the addition of 

 7 genera, 8 species, and 16 subspecies; together with 67 changes in generic, 

 subgeneric, specific, and subspecific terms, involving altogether 90 names. 

 Furthermore, there are 14 eliminations from the North American list as now 

 understood, these consisting of 7 genera, 1 species, and 6 subspecies. 



H. C. O. 



PROCEEDINGS OF THE ACADEMY AND AFFILIATED 



SOCIETIES 

 PHILOSOPHICAL SOCIETY 



853d meeting 



The 853d meeting of the Philosophical vSociety of Washington was held 

 in the Assembly Hall of the Cosmos Club October 8, 1921. It was called 

 to order by President F.\ris with 44 persons present. 



The first paper of the evening, on A furnace temperature regulator, was pre- 

 sented by Mr. H. S. Roberts, 3d, and was illustrated. It was discussed by 

 Messrs. Pawling, White, L. H. Adams, and others. 



This paper was a description of a thermo-regulator for use with electric 

 resistance furnaces and an account of its operation. 



The apparatus is a modification of the regulator described by White and 

 Adams in 1919, in which the heating coil of the furnace is placed in one arm 

 of a Wheatstone bridge and the supply of energy to the furnace varied in a 

 single step by means of a switch operated by the galvanometer of the bridge. 

 In the White-Adams apparatus the switch was moved by a motor-driven 

 mechanism and could only open or close at particular instants separated 

 by arbitrarily fixed intervals of about one second. In the present regulator 



