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Webster 1913 Edition
Patagium
‖
Pa-ta′gi-um
,Noun.
pl. 
Patagia 
(#)
. [L., an edge or border.] 
1. 
(Anat.) 
In bats, an expansion of the integument uniting the fore limb with the body and extending between the elongated fingers to form the wing; in birds, the similar fold of integument uniting the fore limb with the body. 
2. 
(Zool.) 
One of a pair of small vesicular organs situated at the bases of the anterior wings of lepidopterous insects. See Illust. of 
Butterfly
.