96 BULLETIN OF THE 



period. Indeed, it seems likely that this genus does not range up to 

 the \evy summit of that series, but passes out of existence shortly after 

 the Middle Cretaceous section. Therefore the occurrence of this fossil of 

 itself affords fair ground for concluding that the deposit does not belong 

 to a higher level than the Middle Cretaceous. The species of Camp- 

 tonectes has never been found above the middle of the Cretaceous series. 

 Indeed, it appears to be characteristic of the lower portion of that sec- 

 tion. It may be taken as evidence, that the beds in question do not ex- 

 tend below the horizon of the Cretaceous. The other fossils which are 

 described and figured are less determinative in their value. They are, 

 however, so fiir as it has been possible to identify them, not inconsistent 

 with the hypothesis that these beds are of Cretaceous age, and that 

 they probably belong in the lower portion of that period. 



In the present stdte of our knowledge concerning the field from which 

 these Cretaceous fossils are derived, it does not appear worth while to 

 undertake any description of the species. Although the material is in 

 fair condition for such work, it seems to me likely that further study of 

 the field will develop much better specimens. I have therefore sought 

 to do no more than refer these species to their genera, with suggestions 

 as to the apparent affinities of certain forms. In preparing tliis list, I 

 have been so fortunate as to be able to confirm my general determi- 

 nations by the advice of Dr. C. A. White, Palaeontologist of the U. S. 

 Geological Survey. My thanks are due to him, and also to my assist- 

 ant, Mr. Aug. F. Foerste, for a careful search of the island of Martha's 

 Vineyard, in order to determine wliether localities other than those I 

 had found existed on the island. Although the result of this was purely 

 negative, it has been of value to the investigation. I am also indebted 

 to Mr. Foerste for the preparation of the drawings figured on Plate II. 

 of this report. 



The foregoing report is intended as a preliminary statement concern- 

 ing the Cretaceous rocks of this interesting locality. I hope to explore 

 the field by systematic excavations, and thus secure more complete and 

 accurate information than has here been presented. 



