MICROSCOPICAL STRUCTURE OF DIATOMITE 107 
NOTES 
THE MICROSCOPICAL STRUCTURE OF DIATOMITE 
J. K. Creighton 
Owing to some mistake or mishap photo -micrographs of the 
Diatoms of the Kiriandus Deposits of the Rift Valley which 
were expected to arrive from England in time to publish in 
the first number of this Journal did not turn up. 
Mr. Hobley therefore asked me to try to photograph the 
Diatoms for the second number. 
Figs. I and II show some of the forms from the valley 
of the Enderrit River, four miles S.W. of Elmentaita (Mag. 
700 diameters). 
Fig. Ill those of the deposit in the Kedong Valley (Mag. 
900 diameters). 
Fig. IV is diatoms from a small stream in Parkland s 
(Mag. 600 diameters). 
On the average the Frustules from the Kedong Valley 
deposit are much more minute than those from Elmentaita and 
very different in form, the typical Frustule in the Kedong 
Valley being a bamboo or nutmeg-grater shape. 
Very few of these are to be found in the other deposit and 
so far I have not come across any in the living state. 
The above photographs only show a few of the larger 
diatoms, besides these there are many others so minute and 
with markings so fine that they would require the finest high 
power apochromatic objective to resolve them. 
Figs. I, II and III were taken with a Zeiss 8 mm. apochro- 
matic, kindly lent me by Dr. Marsh. 
Fig. IV was taken with a Ross achromatic J" and green 
screen. 
The lighting used in each case was a small acetylene bicycle 
lamp. 
Vol. L-— No. 2. 
i 
