12 Bulletin 35 160 



Page 12 



When a portion of the rock is submitted to heat and 

 the asphalte thus driven off, the Nummulites generally 

 fall into two pieces, each of which, presents a good 

 transverse section of the shell, showing very plainly the 

 internal structure. Were it not for this curious circum- 

 stance it would have been difficult to have obtained sections 

 of these shells, as owing to their fragility they would 

 scarcely bear the process of grinding down however deli- 

 cately conducted. 



Some specimens of Bryozoa have occurred among 

 the Orbitoides, but I have not succeeded in detaching a 

 specimen. They are so brittle that the most careful manipu- 

 lation is insufficient to prevent them from falling to powder 

 under the hand of the operator. I have not detected any 

 other organic remains in the same bed as the Orbitoides 

 and Nummulites ; but both above and below it are found 

 tertiary fossils probably not of more recent date than the 

 Miocene age. I hope to be able to present my observations 

 respecting those fossils in a collected form at some future 

 time. Suffice it to say for the present that the evidence 

 derived from them does not, so far as I yet know, militate 

 against the presumption of the Middle Tertiary origin/pf , 

 the deposits in question. We know too little of tlie 

 Tertiaries of this part of the world to be able to pronounce 

 a more decided opinion ; but should the supposition of the 

 Miocene age of this group be shown to be well founded, 

 we should have here the remarkable phenomenon of the 

 association of an Old -World with a New World form of 

 Lower Tertiary Rhizopod in a deposit of Middle Teritary 

 age. It would be very possible in that case that the 

 homotaxical representatives in Europe of the deposits at 

 San Fernando may be found amongst the lowest members 

 of the Miocene group. But this observation must not be 

 taken to apply to those portions of the Tertiaries which are 

 found further inland, at Jordan Hill, St. Croix, and Mont- 

 serrat, for instance. The fossils from those places, as well 

 as those from Manzanilla, and other parts of the East coast 

 of Trinidad, seem to me to belong to a later date. 



P. S. — Since writing the above, I have observed in the 

 Quarterly Journal of the Geological Society, an account 

 of the association of Nummulince with Orbitoides in some 

 Tertiary beds in the Island of Jamaica, It seems to me 

 very probable that these Nummulince and Orbitoides are 

 identical with those found at San Fernando. (Quart. Journ . 

 Geol. Soc. , vol. 19, p. 514. ) The paper referred to contains 

 valuable remarks on the affinities of the Foraminifera 

 mentioned. 



