166 CONCHOLOGIST’S COMPANION. 
be mistaken. The common Chickweed, and the 
different species which constitute the genus Helix, 
are apparently of little worth: yet the former, during 
winter, is nearly the sole support of innumerable 
flocks of birds; and, without the latter, a consider- 
able proportion of the animal creation would be 
entirely destitute of food. In the formation of 
both, the Creator has deviated from his usual course, 
to provide for their security, and to compensate for 
all their various and necessary defects. 
The numerous species which compose the genus 
Helix; Snail, or Spiral, are principally land or fresh- 
water shell-fish. A considerable number inhabit 
aquatic plants; some are found on trees or shrubs ; 
and others in decayed wood. They also abound 
in the most unfavourable and arid situations. The 
few solitary vegetables which occasionally diversify 
the extensive sands on the south side of the Tagus, 
are incrusted with a species of small snail. Such is 
also stated by African travellers to be the case in the 
deserts of Sahara. 
Two hundred and fifty-three species are assigned 
by naturalists to this extensive genus: some of 
which are beautifully marked; and some of rare 
occurrence. Of these, the H. sultana and H. hemas- 
toma, Variegated and Rose-lipped Helices, are two 
of the most admired; particularly the latter, for its 
elegant zones and rose-coloured lip. 
