GAPERS. 289 
the razor-fish feels the salt, it thinks the tide is 
coming in, and therefore rises in its hole.* 
“Tf the Solen be taken out of its hole and placed 
upon the sand, it immediately prepares to rebury 
itself. It stretches out its foot to full length, and 
then bends it so as to use the extremity as a sort 
of auger. When the end has sunk into the sand, 
it draws up its shell, which, first oblique, and after- 
wards perpendicular, soon becomes immersed and 
rapidly disappears. M. Deshayes, during his 
Algerian researches, observed a remarkable in- 
stinct of S. marginatus to swim when desirous of 
changing its locality. When it finds itself on 
ground too hard to be penetrated by its foot, it fills 
the cavity of its mantle with water, and then con- 
tracting and closing exactly at the same time its 
siphonal orifices, elongates its foot ; then recontract- 
ing that organ, it ejects the water with force from 
the tubes, and thus propels itself after the manner 
of a cuttle-fish for a foot or two forwards. Then if 
it finds the surface favourable, it bores and buries 
itself, but if not, it makes another leap to try its 
chance anew.’ ’t 
Famity MyYApa. 
(Gapers.) 
A large assemblage of genera of small importance, 
presenting considerable variation in external form 
and appearance, but having much more in common, 
may, ina work such as the present, be conveniently 
associated under the above title, the more especially 
as they are united in one family by M. de Blain- 
‘ville. He has named the group Pyloridea, includ- 
* Forbes and Hanley, i. 244. + Ibid. i. 245. 
U 
