1882.] 109 [Zirkel. 



But I think other well proved facts show positively that the 

 above quoted objection is untenable. Mr. Weismann quotes from 

 Lycaena Agestis a summer and winter form in Germany — and 

 in Italy a summer form (which is the German winter form) and 

 a new winter form. Both breed true in their districts, and the 

 two ends of a line are thus represented by distinct forms, although 

 nobody will claim them to be different species. P. Hippocrates 

 is also a similar form. I believe that all forms quoted above are 

 nothing but local cases of one species, of which the first described 

 is P. Machaon. Perhaps the list of local forms of P. Machaon 

 may even be still larger than given by me here. 



General Meeting, November 1, 1882. 



The President, Mr. S. H. Scudder, in the chair. Nineteen 

 persons present. 



The following papers were read : 



SOME REMARKS UPON THE PETROGRAPHICAL COLLEC- 

 TION OF THE GEOLOGICAL EXPLORATION OF THE 

 FORTIETH PARALLEL. 



BY DR. F. ZIRKEL. 



The first criticisms which Dr. M. E. Wadsworth in his paper "On 

 the Classification of Rocks " * made upon the lithological deter- 

 minations of the specimens collected by the U. S. geological sur- 

 vey of the fortieth parallel, I have preferred not to answer. 

 Moreover, any reply from me has been lately rendered unneces- 

 sary by a paper 2 written by Dr. N". F. Merrill — without my 

 knowledge — in which he has undertaken to show that Dr. Wads- 



1 Bull, of the Museum of Comp. Zool., Harvard Coll., Cambr., Mass., Vol. v. No. 13 (a). 



2 Proc. Bost. Soc. Nat. Hist., Vol. xxi, Oct. 19, 1881, p. 234. 



