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II. — Notes on the Fungus growing and eating habit of Seri- 
comyrmex opacus^ Mayr. By Feederic W.Ueich, F.E.S. 
[Read Dec. 5th, 1894.] 
In Bull, de la Soc. Vaud. des Sc. nat., Yol. xx., No. 91, 
1884, p. 49, Dr. A. Forel called attention to the near 
relationship of the genera Atta, Glyptomyrmex, Cypho- 
myrmex, Sericomyrmex apterostigma^ etc., and in Mitth. 
der Schweiz. entom. Ges., Bd. 8, Heft 9, 1892, he unites 
these genera in a special group, the Attini/' under the 
subfamily Myrmic'idee. This was done on morphological 
grounds, and Dr. Moller, in his fascinating work,* fully 
confirms biologically Dr. Forel's hypothesis in proving that 
the genera Apterostigma, GlyptomyrmeXy and Cyphomyr- 
mexj are, like the genus Atta, mushroom growers and 
eaters. Species characterized by this habit are well re- 
presented in Trinidad, viz. — 
Atta cephalotes, L. 
t A. {Acromyrmex) odospinosa, Reich. 
t A. {Tr achy myrmex) urichiif Forel. 
t Apterostigma urichii, Forel. 
t A. mayrij Forel. 
To this list and in support of Dr. Forel I have to add 
Sericomyrmex opacus, Mayr, whose mushroom growing 
and eating habits do not seem to have been previously 
recorded. The nests of these ants are found commonly 
about Port of Spain, in gardens, in the grass as a rule, 
but sometimes in the flower beds, and from their peculiar 
raised entrance can readily be recognized. They are 
always excavated in clayey soil, and the raised entrances, 
which are more or less cylindrical, are constructed with 
the particles of earth resulting from their mining opera- 
tions and are about an inch in height. In young colonies 
this entrance leads into a small chamber, about six inches 
below the surface of the ground, situated, not at the end 
of the gallery but either to the left or right of it. As 
the colony increases the ants do not enlarge this original 
chamber, but, piercing its side, form another chamber 
near it with a small entrance hole. In large colonies, 
which never consist of more than about 200 individuals, 
* Die Pilzgarten einiger siidamerikanisclier Ameisen von Dr. A. Moller, 
Jena, 1893. 
t For descriptions see An. de la Soc. Ent. de Belg., t, xxxvii., 1893, p. 586. 
TRANS. ENT. SOC. LOND. 1895. — PART I. (APRIL.) 
