I 80 1 
teristic members of the litorEil fauna, lound almost everywhere 
attached to rocks between tidal marks. Their shell has the 
shape of an oval saucer. Closely allied are the Key-hole 
Limpets iFissunilii^ which have a slit at the top of the shell. 
The Ormers or Sea-ears {Haltotis) have beautiful pearly shelh, 
up to 6 inches in length. The shells are perforated with a 
serits of holes to admit the water to the gills. They also live 
in shallow water, attached to rocks like the limpets. Other 
well-known forms belonging to this order are Trochus (see pL 
XIX, fig. 2), and Turbo, The latter has a thick and globular 
shell, with some resemblance to a spinning top» as the name 
indicates, and takes a brilliant polish, lis opercuJa are much 
used for ornaments, like rings and brooches. 
(2) The Prosobrdnchiala are thus called because the 
branchial cavity and the auricle of the heart He in front of the 
ventricle. An operculum is nearly always present Most 
marine Gastropods belong to this order, and also some land and 
freshwater forms. The freshwater species include Pahidma, 
AmpuUarki and Mdania. Pa!udina (also called Vknpara) lives 
in swamps or in the mud of rivers It has a greenish globular 
shell and is viviparous. Ampulkma is similar, but la''ger and 
is restricted to the warmer parts of the world. Afelama has a 
turriculated (i.e. spire-like) shell, the lop of which is almost 
invariably eaten away, it is dark brown in colour. All these 
three species have an operculum. Of terrestrial species 
Cydophonts maltiyaims is common on the hills of the Malay Penin- 
sula. Its name is due to the disk-shaped operculum with which 
it is provided. No such opercula exist in the vast majority of 
the land snails which constitute the next order, the Pulmonata, 
Closely allied tr> Cychphonis is a curious looking shell, Hybocys- 
lis elep/hts, which is also found on the Malay Peninsula. This 
shell is, probably both on account of its strange shape and of 
its scarcity, used by Sakeis as ornament, chiefly on necklaces. 
The last but one of its whorls is curiously inflated. Its generic 
name is therefore quite appropiate, as the first part of it 
signifies ' hunchback.' The marine species include many 
well-known forms, such as may be seen at any time in the 
streets of Singapore, especially on mail days when they are 
being carried about by innocent-eyed Malays for the benefit of 
perspiring passengers. There is the Spider-shell iPteroceras), 
with its claw-like projections (see pi. XIX. fig. 3) ; Phorus 
Solaris, a flat shell, with ray-like spines (see pi. XIX, fig. 6) ; there 
are the numerous species of Cowrie-shells {Cypraea) of which 
a small yellow kind (C. moneta) is used as coin by some 
