136 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
and Retreat, and the Catadupa and Cambridge outerops were the only 
fossiliferous beds found. 
The statement of Barrett,! that Orbitoides “are Cretaceous fossils in 
Jamaica,” may possibly have been based upon a knowledge of the asso- 
ciation of these forms with the Cretaceous Rudistes. 
In view of the facts presented, the writer finds it utterly impossible to 
accept the “rolled” hypothesis, and he can see no way of avoiding the 
positive conclusion that the Rudistean forms in the Cambridge beds rep- 
resent a survival of Cretaceous types into tho Lower Eocene. Such an 
occurrence would in no manner be more anomalous than many other 
facts connected with the peculiar insular faunas of late Cretaceous 
and early Tertiary time in Jamaica, mentioned in this Report. Even 
though the Rudistes should prove to be survivals, this Eocene fauna of 
Catadupa as a whole shows anomalies comparable to those exhibited by 
the Jerusalem beds, which mark it as peculiar. As a fauna, nothing 
exactly analogous to it is known elsewhere. 
In view of the apparent mixture of Cretaceous and Eocene forms 
question might arise concerning the position of these beds in tho geo 
logical column. Inasmuch as all the other genera are Eocene, it ig our 
opinion that it will be best to consider the beds of that age and to assum? 
that the Rudistean genera have transgressed into the Eocene. 
The fact that these beds are stratigraphically above the Richmond 
beds is another consideration which leads us to the Hocene conclusion. 
Inasmuch as the two species of coral from the latter (mentioned on page 
126) attest the Eocene affinities of the latter beds, the discovery of the 
Cambridge formation gives a certainty to the existence of an Eocen® 
system in Jamaica, aggregating at least 1,500 foot in thicknoss, which, 
in connection with the Montpelier beds to be described farthor on, of 
supposed Vicksburgian facies, shows the Eo-Tertiary beds of tho island 
to be far more extensive than hitherto supposed. The paleontologi? 
peculiarities of the Richmond and Cambridge formations, analogous t° 
those of tho preceding Cretaceous beds, are such as can only be at 
counted for by geographic environment, and point to the early insularity 
of the island through Eocene time. 
The relations of this fauna to other regions of the world is anomalou® 
Its affinities in some respects seem more analogous to those of the south- 
ern portions of Europe than to those of the United States, but we do not 
dare at present to make positive conclusions except to agree with Moor? 
1 Jamaican Reports, p. 76. 
