502 EEPOKT— 1893. 



VI. Report by Mr. David Robertson, F.G.S., F.L.S., Mem. Imp. Boy. 



Zool. Botan. Soc, Vienna. 



The portion of shelly clay from Clava entrusted to me for exami- 

 nation was, with the exception of a small bagful, chiefly in one piece, 

 taken at 2| feet from the top of the ' main section,' and in a box of broken 

 pieces of stony clay from the bottom of the same section. I had also 

 packages of clay, sand, and gravel from other parts of the deposit, as 

 hereinafter mentioned. 



1. The clay in the above-mentioned bag, being taken from different 

 parts of the section, was considered to be a fair sample of the shelly clay. 

 It consisted of — 



90 per cent, mud ; 

 7 „ sand, mostly angular (grey) ; 

 3 „ stones. 



None of the stones was noticed to be striated ; some — chiefly sand- 

 stones — were angular ; the others were mostly water- worn and well 

 polished. None was much larger than a gooseberry. There may have 

 been a little more sand in this instance, as some of the finer portion may 

 have passed off with the mud. Mica scales were plentiful. 



The clay seemed to indicate deposition in still water, showing no 

 traces of strong currents, and containing few stones, and those mostly 

 small in size. 



2. The shelly clay, 160 yards south-west of the ' main section,' con- 

 sisted of — 



82 per cent, mud ; 

 16 „ sand (grey) ; 

 2 „ stones. 



The stones were water-worn. No striation was detected. 



3. The sand in a tin box, taken from 2^ to 3 feet above the shelly 

 clay of the ' main section,' was in lumps requiring some force to break, 

 and was still harder when dry. It consisted of- — 



34 per cent, mud ; 



64 „ light-coloured fine sand ; 

 2 „ per cent, stones. 



None of the stones exceeded the size of a pea. 



The sand is very fine, mixed with a few small stones. No marine 

 organisms were detected in it. On the whole, it had much the character 

 of blown sand. It was much lighter in colour than the saud washed out 

 of the shelly clay, and contained little or none of the dark mica prevalent 

 in the latter. 



4. The stony clay, being bottom part of the shelly clay, near west 

 end of ' main section,' consisted of — 



48 per cent, mud ; 



24 „ sand, with many red grains ; 



28 „ stones. 



These stones were water- worn. No striation was noticed. 



In this stony clay six Foraminifera and one Ostracod were obtained. 

 Independently of the finding of Microzoa, I was doubtful whether this 

 was part of the shelly clay, or had got mixed with it, or whether an 

 error had occurred in some other way. To make sure of this point 

 another portion was prepared, and here Foraminifera were still more 



