22 
GUIDE BOOK TO THE BRITISH MUSEUM. 
on the hinder part of the upper lip, as the virgin slit-mouthed shell, 
from China. 
Tables 5, 6. The Cone Shells, among which is to be seen 
the celebrated Glory of the Sea ( Conus Gloria Maris'), from tlie 
Philippines; it is very like some varieties of the cloth of gold. 
The setting sun cone ( Conus Vespertinus), from the east coast of Africa. 
Tables 6, 7. The Spindle Shells ( Fusus ), and the Pear Shell {Py- 
rula) ; some of the shells have the whorls always turned in the contrary 
direction to the usual one, and have hence been called reversed ; as 
the reversed spindle shell, from Sicily, or the Crag Rocks, and the re- 
versed pear shell. It is commonly believed that reversed shells of this 
kind are only found fossil ; but this is not the case, and reversed spe- 
cimens of shells which have the whorls in the usual direction sometimes 
occur ; but they are monstrosities, produced by some accident of the 
animal before it is hatched. Specimens of the common whelk, and one or 
two other shells of these kinds are to be seen in the collection ; but they 
are rare, and hence persons have been induced to believe that reversed 
shells are always very valuable, but this is not the case. A specimen of 
the reversed spindle shell, of the reversed bulimus, or of physae or clau- 
silise, with the whorls in the common direction, would be as rare and 
valuable as reversed shells of those kinds which are generally of the 
common direction. The large Chinese spindle shell, which grows to a 
large size. 
Tables 7, 8. The Turnip Shells ( Turbinella), some kinds of which 
are very large and heavy. They are generally spotted when young, 
and white when adult, and from their form have been called Turnip 
Shells or Rape Shells ; these are often used as oil vessels in the Indian 
temples, and for this purpose are carved and otherwise ornamented, 
as may be seen by some in the collection. When reversed they are 
much sought for by the Ceylonese, and highly valued ; one of these 
reversed clamp shells is in the collection : they are said to sell for a very 
large price in Ceylon and China. The Iris wave, ( Turbinella pris- 
matica ,) so called, because when the shell is wetted the periostraca 
gives out brilliant prismatic reflections. The tulip shells, ( Fasciolaria ,) 
among which is a kind which is by far larger than any other univalve 
shell yet discovered. The ostrich foot, ( Struthiolaria ,) and the 
pelican’s foot, ( Aporrhais . ) 
Tables 8 — 11. The genera allied to Buccinum. 
Table 8. The helmet shells, ( Cassis,) some of which grow to a very 
large size, and are used to form cameos. 
Table 9. The Cassidea. The false helmet ( Cassidaria ). The 
harp helmet {Cyathura). The tun, (Dolium,) which are often used 
in tropical climates to bale boats with. And the harps, ( Harpa ,) so 
called because the ribs left on the surface by each succeeding addition 
to the growth of the shell have been compared to the strings of a harp. 
In some species these ribs are far apart, in others close ; the latter are 
called the double-stringed or ridged harp ; they were formerly very rare. 
Table 10. The purple shell, {Purpura,) so called because, like 
many other of the animals of this kind, they emit a purple secretion 
which has been used in dyeing. The unicorn shell, {Monoceros,) 
so called because of the tooth-like horn on the front of the edge of the 
outer lip. The planaxis, which has been confounded with the peri- 
