604 Marvels of the Universe 
In the foregoing cases the resemblances have been produced in the actual shells, but there are 
Snails which are known to adopt certain external aids to concealment. For instance, the Lesser 
Bulin, which has a glossy shell and feeds upon the immature mosses on the bark of trees, covers 
its shell with slime and drags it through the débris to be found in the crevices of the weather-worn 
bark, repeating the process until the shell is entirely concealed and the birds pass it by as a knotted 
excrescence of the bark. The Pellucid Glass Snail, again, has formed the habit of attaching to itself 
bits of leaves or soil, which entirely cover and conceal both shell and animal. But the Snail which 
has succeeded best in disguising his home is the Carrier Snail of Borneo. The denuded shell is in 
shape like a top-shell ; but the Snail secretes a cement by which he fixes all manner of stone, shells, 
and other débris to the top of the successive whorls. The result is that the whole creature is com- 
pletely hidden under this conglomerate mass. 
There are several varieties of Carrier shells, all with the same propensity, though while some 
Photo by) - ey oe ; [/. J. Ward. 
CARRIER SHELLS. 
The owners of these queer dwelling-places will take great pains in their adornment. In some specimens only a certain kind 
of shell or stone will be used (but this may be due to a limited choice of building material), and these particles will be inserted 
to outline the different whorls of the shell. 
appear to favour the larger and rougher pieces of rock and to set them in the cement more 
carelessly, other Carriers choose minute particles of shell or stone, which are very carefully and 
regularly set in the cement and neatly outline the successive whorls of the shell. There is, however, 
more arrangement in this queer device than meets the casual eye, for the choice of material is 
not altogether haphazard, as certain Snails appear to have a preference for certain ornaments. 
For instance, a specimen dredged up during the Challenger Expedition is ornamented entirely with 
long and pointed shells ; others are set entirely with stones, and one large specimen, about six 
inches in diameter (also from the Challenger collection), bristles exuberantly with a species of 
oyster-shell. There is only one Carrier that is not worthy of the name. That is the Indian 
Carrier, who plasters his shell with cement alone ; but this is laid on in a very delicate and fine fan 
pattern. There is one other unornamented Carrier, but he neither cements nor adorns his house, 
and fer a very good reason; for the lower edge of the whorls branches out into flat spines, and 
these take the place of extraneous ornament. 
Outward appearance seems to point to the fact that this species has evolved its peculiar 
