VI INTRODUCTION. 



additional attention to the localities ; and we thank the owners of 

 the plates for their kindness in allowing their use. Each illustra- 

 tion is credited to its source. 



It was intended originally to insert in the paper a section upon 

 land plants; but it has been deemed unnecessary, because the 

 New England Botanical club has made arrangements to conduct 

 excursions and to furnish guides for visitors. 



J. Edmund Woodman. 



Geological Laboratories, Miis. Comp. Zoi/l., 

 Cambridge, Mass. 



August, 1898. 



