292 B. GRASSI AND A. SANDIAS, 
Similar galleries also occur in the spacious ceiling of the 
Benedictine church at Catania. 
In the building of the Botanical Garden at Catania the 
Termites have invaded the benches of the school, the book- 
cases and window-frames, &c. Here I found two gutter-shaped 
tunnels over 40 cm. in length on the wall of a room; they 
began from the timber invaded by the insects, and ran along 
the surface of the wall, to finish at a point where no fissure 
was discoverable. 
The direction of the gutter-shaped galleries may vary as 
required ; they are usually vertical or oblique, less often hori- 
zontal, and they may branch in various ways. The tubular 
galleries are mostly short, rarely exceeding 5 cm., and are 
narrower than an ordinary pencil. They serve to connect two 
gutter-shaped galleries or two portions of a nest; and a 
gutter-shaped gallery may become tubular for part of its 
course. 
On one occasion I found a much flattened tubular gallery 
about 15 mm. in width, 4 mm. in depth, and 5 cm. in length, 
and somewhat irregular. This fragile structure was suspended 
from the ceiling, and contained a certain number of Termites; 
there were some apertures at its free extremity (Pl. 17, fig. 38). 
At other times I have found much shorter flattened galleries 
hanging from the ceiling (Pl. 17, fig. 39; Pl. 18, fig. 15). 
The purpose of these structures escapes me, but, recollecting 
the excrescences built on plants by certain tropical Termites, 
I suspect them to be a rude attempt at a nest. A similar 
explanation may perhaps be advanced for the galleries found 
at the Botanical Garden of Catania, which terminated in a 
free extremity. 
Both forms of gallery usually have a diameter from 2 to 6 mm. 
Their lumen varies at different points, and is generally large 
enough to allow several insects to pass at once; the internal 
surface is tolerably smooth, while the outer is irregular and 
rugged. Their colour is variable, but is usually of a chalky- 
grey tint. They are composed of fecal and disgorged matter, 
and of triturated wood. When connected with a plaster cor- 
