NATURAL HISTORY, TORONTO REGION 
Cecidomyia majalis, Bass. Hosts Quercus rubra, 
L., Quercus velutina, Lam. A flat, pouch-like gall 
on the under side of the leaves of the red and black 
oaks. It is clearly produced by a folding of the 
leaf, and in this respect resembles the Acarina and 
Hemipterous types. 
Cecidomyia ocellaris, O.S. Host Acer rubrum, L. 
The red and yellow concentric rings of colour are a 
very noticeable feature of this gall. In a slight 
depression at the centre of these rings the larva 
rests covered with a viscid fluid secretion. 
Cecidomyia pellex, O.S. Host Fraxinus ameri- 
cana, L. This gall is formed by a swelling of the 
blade of a leaflet on each side of the midrib of leaves 
of the white ash. 
Cecidomyia triticoides, Walsh. Host Salix cor- 
data, Muhl. A terminal gall produced by a swelling 
and shortening of the stem of this willow. The lar- 
val chambers are situated in the buds of the affected 
twigs. 
Lasioptera impatientifolia, Felt. Host Impatiens 
biflora, Walt. A monothalamous gall consisting of 
a spindle-shaped enlargement of the midrib of leaves 
of the spotted touch-me-not. 
Neolasioptera perfoliata, Felt. Host Hupatori- 
um perfoliatum, L. A monothalamous gall on bone- 
set, consisting of a spindle-shaped swelling of the 
stem. 
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