ITALIAN PETROLOGICAL SKETCHES 353 



NOTES TO TABLE I. 



1. Fontana Fiesole, Viterbo, H. S. Washington anal, JouR. Geol., IV, 849, 1896. 



2. West slope of Monte Cimino, vom Rath, Zeit. d. d. geol. Ges., XX, 304, 1868. 



3. Mont' Alfina, Bolsena Region, Ricciardi anal., Klein, Neu. Jahrb. B. B., VI, 

 7, 1889. 



4. Sassara, Bolsena Region, Ricciardi anal., Klein, loc. cit., 7. 



5. Monte Rado, Bolsena Region, Ricciardi anal., Klein., loc. cit., 33. 



6. Above Ortaccio, Campiglia, Tuscany, vom Rath, loc. cit., 331. 



7. L'Arso, Ischia, Fuchs, Tscher. Min. Mitth., 1872, 230. 



8. Scoria, Le Cremate, Ischia, Fuchs, loc. cit., 231. 



9. Radicofani, vom Rath, Zeit. d. d. geol. Ges., XVII, 405, 1865. 



10. Radicofani, doleritic variety, Ricciardi anal., Mercalli, op. cit. post. 



11. Radicofani, andesitic variety, Ricciardi anal., Mercalli, op. cit. post. 



which sum up about the same, but whose relative proportions are 

 quite different. Ricciardi's two analyses of "olivine-bearing 

 andesitic trachyte," Nos. 3 and 4, are quite typical, though the 

 alkalies are rather low, as is generally the case in his analyses. 

 These rocks evidently belong to the ciminites, as has been noted 

 on a previous page.' It seems proper also to class with the 

 ciminites the so-called augite-andesite of Monte Rado in the 

 Bolsena region^ on the strength of Ricciardi's analysis (No. 5), 

 though it shows rather more iron and less alkalies than the first 

 four. While Klein does not definitely speak of orthoclase as 

 present, he refers the high potash either to the glass or to the 

 presence of orthoclase or anorthoclase among the feldspar laths. 

 No. 6 is of an "augite-porphyry " forming a dike at Campiglia, 

 described by vom Rath, who says that "it does not agree with 

 any rock heretofore described in petrography." It is porphyritic 

 in structure, showing phenocrysts of orthoclase, plagioclase, 

 augite, a little biotite and quartz, and quite abundant, generally 

 serpentinized, olivines, which lie in a light to dark greenish gray 

 groundmass. The rock examined was evidently much decom- 

 posed, but the analysis resembles in general those of the cim- 

 inites, though alumina is decidedly low. 



Analysis No. i yields the following approximate composi- 

 tion : 



'Jour. Geol., IV, 554, 1896. 

 = JouR. Geol., IV, 554, 1896. 



