1912.] NATURAL SCIENCES OF PHILADELPHIA. 



February 20. 

 Witmer Stone, A.M., in the Chair. 



Twenty-nine persons present. 



A resolution was adopted conveying a vote of thanks to Charles 

 Marquedent Burns for an oil portrait of the Recording Secretary 

 presented at the last meeting. 



The Publication Committee reported in favor of publishing a 

 paper entitled " Fixation of Single Type (Lectotype) Specimens of 

 species of North American Orthoptera (Section One)," by James 

 A. G. Rehn and Morgan Hebard (February 9) in the Proceedings. 



The following had been accepted for publication in the Centenary 

 Volume : 



"Description of a new Fossil Porpoise of the genus Delphinodon 

 from the Miocene Formation of Maryland." By Frederick W. True. 

 (February 10.) 



"Mimicry in Boreal American Rhopalocera." By Henry Skinner, 

 M.D., Sc.D. (February 15.) 



"The Petrographic Province of Neponset, Massachusetts," by 

 Florence Bascom. (February 20.) 



Prof. Ulric Dahlgren made a communication, beautifully illus- 

 trated, on the production of light by animals. (No abstract.) 

 The subject was discussed by Dr. Edward Anthony Spitzka. 



Frederick Ehrenfeld and Francis B. Bracken were elected members. 



The following were ordered to be printed: 



