698 MR. K, J. LECHMERE GUPPY ON THE GEOLOGY [Nov. I9II, 



Naparima Series, the differences in mineralogical characters being 

 due to depth of water and other conditions. This has been a much- 

 debated question, 1 and I think that it may now be regarded as 

 settled. The true jSTapariuia Marls, including the foraminiferal 

 and radiolarian series, were deposited in deep and comparatively 

 clear water ; while the jSTariva Series was at the same time formed 

 on the margin of the deep-water area, and subject to invasion by 

 flood-water as well as tide-water. Hence the difference in mineral 

 constitution. The presence of the Orbitoides Bed shows that the 

 Eocene formation probably underlies the whole region. It is 

 exposed wherever brought-up by faults or folds, as at JNos. 4, 6, 7, 

 8, & 15 of the sketch-section from Taruba Creek to the Oropuch 

 Lagoon, vol. xlviii (1892) of this Journal, p. 522. I subjoin a 

 modified copy of that diagram (fig. 4, p. 697), showing the probable 

 position of the Orbitoides Bed in that section. 2 



When writing the paper to which I have just referred, I was 

 still under the impression that Orbitoides and Nummulina were 

 found in West Indian Miocene strata, though I had not so found 

 them myself. My later experience led me very strongly to doubt 

 this, and to regard these foraminifera as characteristic of the 

 Eocene and possibly of even earlier formations. I regret that so 

 much confusion has followed upon this mistake, which I believe 

 was primarily due to the correlation of certain West Indian with 

 Maltese rocks considered to be Miocene but now called ' Oligocene.' 



A noticeable addition to the fauna of the Orbitoides Bed is to be 

 recorded here. It is Corax pristodontits, of which I lately found a 

 tooth in the Orbitoides Bed. This tooth was determined for me 

 by Dr. A. Smith Woodward, of the British Museum (Natural 

 History), and it will be seen that it adds to the Cretaceous 

 affinities of the Orbitoides Bed, already fairly obvious. 



The conclusions here stated vary from those set forth by 

 Mr. Jukes-Browne & Prof. Harrison in their paper on Barbados, 3 

 for I place the line between the Pliocene and the Miocene at the top, 

 and not at the bottom of the Naparima Marls (or Oceanic Series). 

 But, in a note on Prof. Gregory's paper, 4 Mr. Jukes-Browne says : — 



' We are quite prepared to accept Dr. Gregory's conclusion that the Oceanic 

 Series is of Miocene age, the more so as Dr. Spencer has come to the same 

 conclusion with respect to the Radiolarian Earths of Cuba.' 



As this is in practical agreement with my conclusion, I think 

 that it may now be regarded as clear (1) that the Calcareous 

 Formation of Antigua, as also the Orbitoides Bed of Trinidad and the 

 Scotland Beds of Barbados, is Eocene (or older), and that all these 

 formations preceded the volcanic era ; and (2) that the Oceanic 

 Series of both Trinidad and Barbados are Miocene, and coeval 



i See Geol. Mag. dec. iv, vol. vii (1900) p. 322. 



2 See my account of the Naparima Series (pp. cit. p. 523), where I have 

 indicated the position of the Orbitoides Bed at several points. 



3 Q. J. G. S. vol. xlviii (1892) p. 218. 



4 Ibid. vol. li (1895) p. 311. See also G. F. Franks & J. E. Harrison, 

 ibid. vol. liv (1898) p. 550. 



