[ 8J 1 
Eastern races; the Egg-shell {Ovuium ovum) which is pure 
white in colour and resembles a poached egg in appearance 
{see pi XIX fig. 9) > the large Trumpet-shell ( Triton tritonish 
used as war trumpet by the natives of the Pacific islands ; the 
Fig-shell (Fiadti reiicuintti), thus called from its shape, of 
brownish or greyish-blue colour. Common also are the Helmet- 
shells which include some of the largest of univalves like Cassis 
comtda, whilst another species. Cassis rufa, is frequently cut 
into cameos ; the Tun-shells {DoHimt) which are mostly large, 
globose and thin shells, with spiral ribs and grooves (see pl- 
XiX, fig. I); Solarhi/n, a flattened, almost disk-like shell (see 
pi. XIX, fig. 10) ; the Whelks {Buccimim), common here and 
in British seas. Closely allied to the Whelks is the genus 
Fusus of which there are several hundred species. The largest 
of them is Fusils proboscidi ferns, of spindle-like shape, the 
specimen in the Museum measuring not less than 19 inches in 
length. Another very extensive genus is Mitra, characterized 
by a thick and fusiform shell. The best-known of them is the 
Bishop's Mitre {M. cptsc&patis), with its scarlet spots- The 
genus Murex includes some very remarkable and handsome 
species, like M, haustellatum {see pi. XIX, fig. 7), and M. temd- 
spina which is beset with three rows of slender spines (see pi. 
XIX, fig. 5). Some species of Murex and of the allied genus 
Purpura were in ancient times used for preparing the celebrated 
purple. The genera Voiuta and Cymbium comprise some large 
and boat-shaped forms, whidsh or yellowish in colour. Some 
of them are made into spoons. Figured is one of the smaller 
species, marked with undulating lines, Valuta undulata (see pL 
XIX, fig. li). The Harp-shell {Harpa conoidalis) is almost 
without rival in its beauty. In its general shape it is similar 
to the Volutas, but it is beset with numerous longitudinal ribs 
(see pi. XIX, fig. 4), The genus Canrn includes more than 500 
species from warm and especially tropical Asiatic seas. They 
are cone-like in shape. Figured is C. bandanus (see pi. XIX, 
fig. 8). 
(3) In the Opisthobranchiata we find the branchial veins 
and the auricle of the heart placed behind the ventricle. They 
are nearly all marine and are divided into Teciibranchiata and 
Nudibranchiata, according to whether the gills are covered by 
the mantle or not. In some Tectibranchiala the shell may be 
well developed, in others it is much reduced or may be absent 
altogether. To the former belongs the Bubble-Shell {Bidla, 
ampulla), a smooth, egg-shaped shell, painted with dots and' 
blotches like a plover's egg. A collection of them, showing 
