176 
Bulletin 35 
324 
To prevent misapprehension I should note that the term 
“deep-water” is a relative one and that while the Ditrupabed 
maj- be said to be ‘ ‘deep-water’ ’ as compared with the Springvale 
Shellbed it was laid down in much shallower water than the 
Naparima oceanic beds. The Foraminifer Planorbulina larvata 
is characteristic of a depth from 15 to 200 fathoms, while Nodo- 
saria abysorum has onh’ been found in the recent state at 1,825 
fathoms. 
I should notice here that the characteristic Foraminifera of 
the Ditrupabed are absent so far as I have examined from the 
exposure discovered b\’ Mr. Raspass. Instead there is an extra- 
ordinary' Abundance of Planorbulina larvata a species only sparse- 
ly represented in the shore exposure at Pointapier, but much 
more plentiful in a sample given me by Mr. Cunningham Craig 
from Tamana Road. I have nevertheless considered the deposit 
discovered by Mr. Raspass to be of the Horizon of the Ditrupa- 
bed on account of its position, mineral composition and molluskan 
Fossils. 
My friend Alfredo Silvestri, Professor R. Liceo of Spoleto in 
Italy, one of the greatest authorities on Foraminifera and es- 
pecially on Orbitoides, considers those from the Manjak mine to 
be Lepidocyclina tournoueri Lera, and Douv. a varity of L. mar- 
ginata Mich, found in Italian Tertiaries. He also finds among 
these Orbitoides a (probably) new species of Lepidocyclina, the 
Page S3 
embryonic part of which is very remarkable. He con.siders the 
Orbitoides from Antigua to be Lepidoc)'clina elefantuia Munier 
Chalmas, a form also found in Italian and Indian Tertiaries 
(Aquitanian). I am unable as I have so often stated to admit 
the validity of the distinctions so much relied on by experts to 
characterize so-called Genera and species. While I have no 
doubt 'as to the correctness of Silvestri’s identifications for my 
own use I prefer the designations already arrived at as referred 
to in my note on the Manjak mine. In estimating the probable 
age of the Naparima Tertiaries we must give due weight to the 
