1884.] NATURAL SCIENCES OP PHILADELPHIA. 295 



Entomology, Department of Agriculture, Washington, D. C, who 

 judged them, after a cursory examination, to be Proctotrupids, 

 belonging to the sub-family Sceliominaj, and seeming to form an 

 entirel}' new genus. Thus appears to be added one more to the 

 parasitic enemies of our spider fauna. 



Rufus Sargent and W. Henr^^ Grant were elected members. 



The following were elected correspondents: — John Ball, of 

 London ; William Carruthers, of London ; Rud. Leuckart, of 

 Leipzig; Anton Dohrn, of Naples ; A. Grenadier, of Halle i. S. ; 

 Alex. Gotte, of Rostock i. M. ; and Ludwig Will, of Rostock i. M. 



December 2. 

 The President, Dr. Jos. Leidy, in the chair. 

 Thirty persons present. 



December 9. 

 Mr. J. H. Redfield in the chair. 

 Tliirty-one persons present. 



On Derivation in Finns edulis and Pinus monophylla — At 

 the meeting of the Botanical Section, on December 8, Mr. T[iomas 

 Meeiian called attention to some dried specimens of Finns mono- 

 phylla on the table, which were received in a fresh condition, a 

 few months ago, from Mrs. Lewers, of Franktown, Nevada. At 

 that time the phyllodes which took the place of the real leaves, were 

 all nionopliyllons. Li drying, several h:id opened in some speci- 

 mens, and others readily separated by a little aid, showing that the 

 species might have been two-leaved, but for some inability in the 

 earl}^ stages of development to separate them. This monophyl- 

 lous species was closely allied to Finns edulis, which was confined 

 to the Rocky Mountains; the monophyllous species being the 

 form that prevailed further west. But in a small tree of P. edulis, 

 growing in a deep ravine in Queen Canon, in the RockA' Moun- 

 tains, he had found on the same tree monophyllous, diphyllous, 

 and triph^dlous phyllodes, and there could not possibly be any 

 doubt that the species were of one origin. The case was one 

 worthy of note, because it had been charged that there was no 

 actual evidence of the truth of the doctrine of derivation. Gener- 

 ally when such evidences as these were offered, the objector was 

 prepared to abandon his belief in the specific distinctness of the 

 forms, rather than to grant that two distinct species had been 

 developed from one parent, and even in the case of these species 



