Wadsworth.] 416 [October 3, 



Having, as I think, shown that Richthofen's and' Zirkel's princi- 

 ples of classification were not in accord, I will proceed to show 

 how Richthofen's system — or rather his species peculiar to it, 

 propylite — has been received in Europe since Zirkel maintains 

 that the system has met with warm sympathy. (Z. 111). In 

 the lithological text books of Zirkel, Lasaulx, and Rosenbusch, 

 published respectively in 1873, 1875, 1877, the name propylite 

 does not occur in the indices, and I have never seen it in the 

 text ; but H. O. Lang, in his Elements, places it under horn- 

 blende-andesite. Justus Roth, in his Beitrage zur Petro- 

 graphie der plutonischen Gesteine, 1879, does the same. Dr. 

 C. Dolter while upholding the Transylvanian propylite, appears 

 to class it as a variety of hornblende-andesite ; while Judd and 

 Koch claim that the Schemnitz propylite is a modification of an- 

 desite, the former even holding that both occur in the same erup- 

 tive mass. Szabo classes both this propylite and andesite as the 

 same rock under trachyte, while vom Rath holds that this same 

 propylite is a pre-Tertiary diabase. Dr. Hussak, however, agrees 

 with Richthofen. Rosenbusch, in a general article on propylite 

 published about the same time as mine, points to the little value 

 of, and the inconsistencies in, Zirkel's diagnostic distinctions be- 

 tween propylite and andesite, and places the former as a simple 

 modification under the latter. In his latest published classifica- 

 tion Rosenbusch puts propylite with a question mark under ande- 

 site, quartz-propylite under dacite, and augite-propylite and 

 quartz-augite-propylite under augite-andesite, thereby taking 

 concordant ground with myself so far as our difference in nomen- 

 clature permits. 1 Zirkel even states in volume VI., page 10, 

 "The vagueness of this diagnosis, founded upon geological prop- 

 erties alone, and wanting well-defined, characteristic lithological 

 distinctions, has prevented the propylitb of von Richthofen from 

 receiving any considerable acknowledgment among European 

 geologists, who doubted its specific independence or the neces- 

 sity of separating it petrographically from hornblende-andesite." 



Having I think proved the correctness of my statement, denied 

 by Zirkel, that Richthofen's and King's classification was not ac- 



l Verhandl. Geol. Reich., Wien, 1879, pp. 17-23,27-29; 1880, pp. 309,310; Min. 

 Petrog. Mitth., Wien, 1879, pp. 1-16; Quart. Journ. Geol. Soc, 1876, xxxii, 292-325; 

 Sitz. neider. Gesell., Bonn, 1878,xxxv,33; Neues Jahrb. Min., 1879, pp. 648-652; 1882, 

 ii, 1-17. 



