540 ME. K. J. LECHMERE GUPPT ON THE 



numerous than in the South Xaparima rock. The stellate bodies 

 are also very abundant. The indefinite light-coloared argillaceous 

 substance is present, and the fragments of this contain numerous 

 small, opaque, black specks, which are doubtless peroxide of man- 

 ganese. Sand grains are fairlj^ abundant, and one slide contained 

 a small angular crystal of brown hornblende. 



(4) Greensand Shell-hed — Ally Creek, South N^aparima. — The 

 matrix of this rock is almost entirely composed of glauconite in the 

 form of irregular grains and dust. These are mostly of the pale- 

 green variety ; the largest grains are dark green ; the brown tj^pe 

 is rarer. A few sand-grains and some argillaceous material are 

 also present. The glauconite seem to show but little evidence of 

 organic origin. A fragment, probably of a tubulated brachiopod 

 shell, is infiltrated with brown glauconite. 



This specimen appears to belong to the sub-littoral zone. 



Microscopic examination suggests that the last-described rock is 

 an ordinary sub-littoral greensand, and that the f oraminiferal marls 

 were formed in deeper water, but sufficiently near land to receive 

 mechanical derived debris. The ' argiline,' which appears to be 

 an indurated red clay, and the radiolarian marls have all the cha- 

 racters of deep-water and pelagic deposits. 



[Mr. Guppy has since sent me a specimen of the ' Ditruj)a-TOGk,' 

 and asked me to examine it. It consists mainly of indefinite argil- 

 laceous substance, and contains a few foraminifera and sponge- 

 spicules. Coccoliths and fragments of radio! aria also occur. A 

 feature which separates this rock from the radiolarian and forami- 

 niferal marls and ' argiline ' is the abundance of very fine rounded 

 grains of quartz. — 3rd Aug.] 



Discussion. 



The Peesident felt sure the Society would welcome once more 

 a paper by an Author whose writings on the molluscan faunas of 

 Trinidad and Haiti were of much value. Those papers were written 

 before the exploration of the deep-sea faunas had been carried out. 



The Society had lately heard the paper by Messrs. Jukes-Browne 

 and Harrison on the deep-sea deposits of Barbados, and the present 

 paper would be useful for comparison with the results of those 

 Authors. It was difficult to understand the conclusions arrived at 

 as to the molluscan fauna after the description of the microzoic 

 fauna, but perhaps some of the Fellows present might throw light on 

 this point. 



Dr. H. Woodward regretted the absence of the Author of this 

 communication, the more so as he was prevented from attending by 

 severe illness. Although he had been unable to visit Mr. Guppy, 

 and so learn his views upon the subject of his paper, he was greatly 

 indebted to Dr. G. J. Hinde for having examined Mr. Guppy's speci- 

 mens so carefully, aud for having prepared and exhibited a series of 

 slides of radiolarian and foraminiferal deposits from the I^aparima 

 Beds of Trinidad to illustrate Mr. Guppy's paper, from materials 

 furnished to him by Mr. J. W. Gregory. 



I 



