684 ME. E. J. LECHMEEE GTJPPY ON THE GEOLOGY [NOV. 10,11, 



though in the latter only small Orbitoides have been found. 1 Owing 

 to this resemblance, I feel convinced that other fossils, especially 

 fish-remains and echinodermata, will be found in this rock. 



P. Martin Duncan and T. Rupert Jones wrote in the ' Geological 

 Magazine ' for 1864 on the fossils and geology of Antigua (pp. 97, 

 102). Their papers were based on the information supplied by 

 Nugent. In my ' Second Note on the Manjak Mine ' (Trinidad, 

 1909) I have quoted from llupert Jones's paper on the Orbitoides 

 of Antigua to show that they are essentially the same as those of 

 Trinidad. Duncan's and Jones's papers were written long before 

 the time of Purves : their principal object was the chronological 

 correlation of the Tertiary strata of Malta and Antigua. The 

 Orbitoides had a great share in this correlation. So far as the 

 relative age of the Antiguan and Maltese strata goes, the above- 

 mentioned writers may be said to have made out a case ; but the 

 assignment of the Antigua Porination to the Miocene must, I think, 

 in view of our present more definite knowledge, be given up. In 

 the discussion which followed the reading of my paper on the 

 Microzoic Pormations of Trinidad, 2 Yaughan Jennings remarked 

 that the difficulty (of determining the age of West-Indian forma- 

 tions) was due to the want of ' accurately-localized specimens and 

 stratigraphical horizon.' Hence we find Orbitoides recorded from 

 the ' Miocene ' or ' Oligocene,' although it is probable that they came 

 from underlying or neighbouring beds. In Dr. Spencer's paper on 

 Cuba certain identifications of fossils are ascribed to me, and I 

 believe this is correct. But, being unacquainted with the deposits, 

 I fear that I followed my predecessors too blindly, and did not so 

 carefully discriminate between fossils from different formations as I 

 ought to have done. I can, however, aver that personally I have 

 never found Orbitoides associated with the truly characteristic 

 Miocene mollusca. It was the differences that I observed between 

 the faunas of the different beds in Trinidad that induced me 

 gradually and tentatively to assign a more ancient date to certain 

 strata. And I think that further observations are needed to clear 

 up the alleged occurrence of Orbitoides in Miocene strata in Haiti, 

 Jamaica, and other islands. 



This may possibly be a suitable occasion for me to say a few more 

 words on the correlation of West Indian deposits of Tertiary age. 

 Even so eminent a Professor as J. W. Gregory has fallen into the 

 common error of mixing up the Miocene with the Eocene, and 

 calling the result 'Oligocene.' In his paper of 1895 3 he refers 

 to two echinoids, sent to him from Antigua as coming from the 

 ' Oligocene ' of that island. Of these, Echinanihus antillarum is 

 stated by Cotteau to be an Eocene species from St. Parts ; while 



1 I have found some 'large thin' Orbitoides in the Orbitoides Bed of 

 Trinidad, but the largest of these is only 12 millimetres in diameter, whereas 

 the Antiguan specimens are 60 mm. in diameter and possibly even larger 

 than this. 



2 Q. J. G. S. vol. xlviii (1892) p. 541. 



3 Ibid. vol. li, p. 295, 



