278 



strata, their position and order of succession as well as their 

 origin and organic contents were imperfectly elucidated ; and for 

 part of this there is the excuse that it is exceedingly difficult if 

 not impossible to obtain anything like clear evidence of super- 

 position among the different beds or formations. It is usually 

 by inference alone that we have to deduce the respective posi- 

 tions and age of the beds. And in this of course there is liability 

 to error. 



The tertiary rocks of Napaiima in Trinidad are described in 

 the Report as a series of marls, conglomerates and calcareous 

 sands. The Report mentions the clitFs of marl, the most im- 

 portant exposure of the series, on the shore of the Gulf of Paria. 

 These cliffs extend some distance north and south of the Town of 

 San Fernando. After alluding to the extensive presence of 

 asphalt in the beds, the Report states the existence of calcareous 

 nodules, thin beds of limestone, and some sandstones, and refers 

 particularly to a stratum to the south of the Town standing out 

 into the Gulf and appearing at first sight like a vei-tical dyke of 

 asphalt. This stratum is figured in the Report and the authors 

 state that on examination they found it to be merely a highly 

 inclined layer of marl with fragments of shells and a large pro- 

 portion of bitumen. This is the bed referred to in my com- 

 munication of July 1863* to the Scientific Association of Trini- 

 dad as being entirely or almost entirely composed of the remains of 

 Orbitoides and Nummulina. I referred to this bed again in 1866 

 when I i-ead to the Geological Society a paper on the relations of 

 the Tertiary formations of the West Indies. Among the illus- 

 trations to that paper was a diagram sketch of part of the coast 

 section near San Fernando,! and Professor T. Rupert Jones was 

 good enough to append a note on the Orbitoides and Nummu- 

 linse.J I had indicated as unfossiliferous certain other beds ex- 

 posed in the coast section. The oolitic texture of these and others 

 of the Naparima rocks had been noted in the Geological Report, 

 but apparently the exact nature of that texture had not oc- 

 curred to the authors any more than it had to me when writing 

 my paper of 1866. A subsequent and more careful examination 

 showed me that the supposed oolitic grains were no other than 

 minute fossils belonging chiefly to the order Foraminifei-a. 



I announced this discovery in a paper read before the Trini- 

 dad Society in 1872 and published in the " Geological Magazine" 

 for 1873. In it I gave the names of fifteen species of forminifera 

 besides those already recognized from the Orbitoides bed. Sub- 

 sequently I published in the " Geological Magazine" (Sept. and 



*Reprinted in " Geologist," 1864, page 159. 

 i-Quart. Journ. Gaol. Soc. vol. xxii (1866) p. 571, 

 + See also Geol. Mag, vol. i, p. 102. 



