April 3, 1903 J 



SCIENCE. 



543 



two yeai's ago, upon ' Some Principles Con- 

 trolling the Deposition of Ores,' it was stated 

 that the metals of some ores are derived di- 

 rectly from adjacent igneous rocks; that the 

 igneous rocks are the ultimate source of all 

 the metals of ore deposits; that igneous rocks 

 have an influence upon ore deposits by con- 

 tributing metals and solutions to them, and 

 a very important effect in heating solutions 

 of meteoric origin. 



As a basis for discussion the following pro- 

 visional genetic classification was submitted: 



Mr. William H. Ashmead was elected vice- 

 president of the Washington Academy of 

 Sciences for the Entomological Society. 



Mr. Ashmead exhibited two species of wasps 

 from Chile. The first, Agenia xanthopus 

 Spinola, is remarkable because of the very 

 short wings possessed by both sexes. ' This 

 species is a synonym of Pompilus gravesii 

 Haliday and will fall into the genus Sphic- 

 tostethus of Kohl. The other species was 

 Cosila chileiisis Spinola, the type of Mr. Ash- 

 mead's family Cosilidse. 



Metallic 

 Ore 



Deposits. 



f (a) Chemical precipitates. 

 {A) Sedimentary. < 



L (6) Mechanical concentrates. 



(B) Igneous. {Magmatic segregations. 



1^ (3 



(1) Residuary deposits. 



Stream deposits. 

 (3) Beach deposits. 



(G) Metamorphic. 



(a) Ores deposited from gaseous 

 solution. 



{( 1 ) Ascending waters. 

 (2) Descending waters. 

 (3) Ascending and descending 

 waters. 



The classing of a large proportion of ores 

 as pneumatolytic, fumarolic, solfataric and 

 pneumato-hydato-genetic, in various recent 

 publications, was deprecated. It was asked 

 ' what are the criteria by which ore deposits 

 are known to be deposited by gaseous solu- 

 tions ? ' If this question can not be satis- 

 factorily answered, what can be said as to 

 the criteria upon which ores deposited by 

 gaseous solutions are again subdivided? The 

 placing of various ore deposits of many well- 

 known districts in such classes as fumarolic 

 solfataric, pneumatolytic, etc., without giving 

 evidence for such a distribution, seemed to the 

 speaker to be premature. 



The criteria by which ores deposited by 

 aqueous solutions may be discriminated were 

 briefly summarized and the conclusion reached, 

 from the application of these criteria, that 

 this class of ore deposits is one of greater 

 importance to men than any other class, and 

 probably of greater importance than all other 

 classes. W. C. Mendenhall. 



Becretary. 



EN-TOMOLOGICAL SOCIETY OP WASHINGTON. 



The 175th regular meeting was held on 

 February 19, 1903, fourteen members present. 



Dr. Dyar presented the description of a new 

 genus and species of Geometrid moths from 

 Stockton, Utah, exhibiting specimens. Ho 

 presented, further, a synoptic table for sep- 

 arating the North American white-marked 

 species of Eucosma, a genus of moths belong- 

 ing to the family Tortricidse, with the de- 

 scription of a new species from Colorado. 

 Dr. Dyar showed also a copy of Volume VII., 

 Number 1, of The Insect World, the ento- 

 mological magazine published in Japanese by 

 Y. Nawa, which contains a colored plate of a 

 moth and larva parasitic upon a leaf-hopper 

 belonging to the homopterous family Ful- 

 goridae. He said that this was of special in- 

 terest in connection with the species found 

 by Messrs. Schwarz and Barber in New Mex- 

 ico and which he had recently described before 

 the society as a new species, Epipyrops har- 

 leriana. The moth figured by Mr. Nawa 

 seems to be also an Epipyrops. It is not yet 

 clearly known what is the food of these larvs. 

 Westwood supposed that they fed upon the 

 white secretion of the Fulgorids, but Mr. 

 Nawa, in his account of the Japanese species, 

 stated that the larvse secreted a white cover- 

 ing, and Dr. Dyar did not think it reasonable 

 that the larvae should secrete a substance sim- 



