476 PROCEEDINGS OP BALTIMORE MEETING. 



The spherulitic phases of the rhyolites require no detailed mention. The speci- 

 mens show for themselves. Although there are, of course, very many small sec- 

 ondary spherulites in these old rocks, the larger ones are believed to be unques- 

 tionably original, not necessarily with respect to their material, but with respect 

 to their structure, which, by the way, is as beautifully radial as it is in some of the 

 spherulites described by Cross from Colorado. Some of the spherulites in these 

 rocks are hollow and a few possess other lithophysal characters, so that it seems 

 possible to match in these old eastern rocks most of the peculiarities of the modern 

 lavas of the far west. 



From this very brief and by no means satisfactory description of the rocks about 

 Vinal Haven and North Haven it would seem that we have in this region nearly 

 every variety of rock characteristic of volcanic regions. Since we know no way by 

 which a bedded series of glassy and crystalline rocks, amygdaloids and tuffs may 

 be laid down except through volcanic agency, we are led perforce to the conclusion 

 that in ancient times a volcano was situated in the neighborhood of Penobscot bay, 

 and that from it as a center lavas and ashes were spread over the surrounding 

 region. It is hoped that a search will reveal the exact location of the vent through 

 which these products were erupted. Mr G. 0. Smith will probably make the study 

 of the rocks the subject of his thesis at the Johns Hopkins University, so that 

 we may hope soon to know something more definite about their relations to the 

 Niagara limestone and sandstones with which they are associated than is known 

 at present. 



The paper was discussed by A. C. Lane, J. P. Iddings, Whitman Cross, 

 J. E. Wolff, J. F. Kemp, T. G. White (by invitation), W. S. Yeates and 

 C. H. Hitchcock. 



The following two papers were by the same author : 



PERIPHERAL PHASES OF THE GREAT GABBRO MASS OF NORTHEASTERN MIN- 

 NESOTA 



BY W. S. BAYLEY 



Remarks were made by A. C. Lane. The paper is published in the 

 Journal of Geology, volume ii, pages 814-825, and volume iii, pages 

 1-20. 



The following was an exhibition of specimens : 



CONTACT PHENOMENA AT PIGEON POINT, MINNESOTA 

 BY W. S. BAYLEY 



This paper is published as Bulletin 109 of the United States Geological 

 Survey. 



