RECORDS OF MEETINGS OF 1907 337 



Pantelleria and Linosa, which he visited for the Carnegie Institution in the 

 summer of 1905. The Catalonian eruptions are referred to two phases, a 

 first of extensive lava flows, followed by the formation of numerous small 

 cinder cones, the material being basaltic in every case, nephelite appearing 

 in some types. The Sardinian occurrences consist of extensive sheets of 

 basalt and trachyte of Tertiary age, v^ith the two later large volcanoes of 

 Monte Ferru and Monte Arci, both of which show an interior core of salic 

 rocks (trachytes and phonolites at the former and rhyolites at the latter), 

 covered by extensive mantles of basalt. The last phase of volcanicity in 

 Sardinia is seen in a long line of small cinder cones of recent date, much 

 resembling those of Catalonia in both form and material. The island of 

 Pantelleria is quite complex, but here also the earlier eruptions were of 

 trachytes and phonolites, the activity closing with the formation of small, 

 basaltic, cinder cones. The small islet of Linosa, which is almost unknown, 

 shows nine volcanic cones, two phases of eruption being evident: the first 

 producing basalt tuff cones, and the second basaltic cinder cones, similar 

 to those from the other localities. The paper was illustrated by numerous 

 photographs taken by the speaker. 



The papers of Dr. Ogilvie and Professor Kemp and Mr. Ross have 

 been published in Vol. XVII, Part II, of the Annals. 



The Section then adjourned. 



Edmund Otis Hovey, 



Secretary pro tern. 



SECTION OF BIOLOGY. 

 May 13, 1907. 



Section met at 8:15 P. M., Vice-President Crampton presiding. 



The minutes of the last meeting of the Section were read and approved. 



The following program was then offered: 



Henry F. Osbom, Brief Account of the Expedition to the Fayum, 



Egypt. 

 Edmund B. Wilson, The Supernumerary Chromosomes of Hemiptera. 

 L. Hussakof , Variations in the Leaf Type of Liriodendron tulipi- 



fera during a Season's Growth. 

 A. W. Grabau, Orthogenesis in Gastropods. 



