96 BULLETIN OF THE 
period. Indeed, it seems likely that this genus does not range up to 
the very 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 far 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 state 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 this list, I 
have been so fortunate as to be able to confirm my general determi- 
nations by the advice of Dr. C. A. White, Palzontologist 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 whether 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. © 
