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coast. I must depend entirely upon others for the raw material. 
My plan of operation is to order the muds from the deep water 
where vessels are anchored. When this is received and examined, 
I order again from different locations where oysters abound, for 
it is a well-known fact that the oyster muds always contain many 
beautiful forms. On the Gulf coast there are three classes of 
muds—blue, black and gray. I always select the blue muds. In 
Tampa Bay, Florida, the bottom is composed of three distinct 
classes of marine and vegetable matter. There is a white marl, a 
black mud and a blue mud. Asa rule it is only the blue mud 
that is productive. I have often read with surprise the remarks 
of eminent diatomists on the avoidance of marine muds. I am 
now offering a cleaning from Tampa Bay, which I challenge the 
world to duplicate from the same material. Those who receive 
it will find it to contain beautiful specimens of Avwliscus pruino- 
sus, Auliscus celatus, Triceratium favus, Niteschia circumsuta, 
Eupodiscus radiatus, Eupodiscus Argus, Orthosira marina, Am- 
phiprora elegans, Terpsinée musica and Surirella Febigerii. 
_ The mud from which these vigorous forms are obtained is one 
of the most difficult to clean, that is to eliminate the sand, of any 
on the Gulfcoast. The result obtained, however, more than pays 
for the labor expended. In cleaning these muds I have used as 
much as two hundred and fifty gallons of water before I obtained 
enough material, in a cleaned state, to cover the bottom of a_half- 
drachm phial. I have now on hand a specimen of this kind from 
Apalachicola Bay, which took three gallons of mud and the 
above named quantity of water to thoroughly wash before the 
application of acid. The great mistake generally made in clean- 
ing marine muds is that not enough care is taken in the first 
washings with water. My method is to remove all sand possible 
before shaking is commenced, for the violent agitation of a mix- 
ture of sand and diatoms is very apt to break some of the most 
__ beautiful forms in the deposit. Another mistake made in clean- 
ing diatoms is by placing too large a quantity of the raw 
_ material in the vessel for the first washing. Only as much 
should be placed in the bottle or jar as will settle in ten 
‘minutes, and this should be repeatedly washed until the water 
will settle clear in a few minutes. The jar should not be shaken, 
