VOLUTID. 163 
seas of Europe, although they were numerous during the tertiary 
epoch; V. abyssicola, an African species, is the sole surviving 
representative of the group to which most of these small tertiary 
species belonged. Australia is the metropolis of the Volutes, 
and, as M. Crosse remarks, a triangle the respective points of 
which shall include Ceylon, Japan and New Zealand will cover 
the habitat of about 80 per cent. of the species. Fossil, 250 sp. 
Cretaceous; Hurope, Asia, N. America. V. musica, Linn. 
(liii, 6). 
Shell ovate or subconical, thick, solid; spire usually short ; 
shoulder of whorls usually angulated, sometimes nodose or 
spinous; aperture generally rather narrow; columella with a 
callous deposit and plaited; lip generally thickened, sometimes 
subreflected. 
Animal having eyes on lobes at the base of the tentacles ; 
siphon with a lobe on each side at its base. Usually no oper- 
culum (there is an operculum in V. musica, Linn.). 
This genus is oviparous, at least the South American species 
are so, and M. Duhant-Cilly has given us some interesting par- 
ticulars concerning them. He noticed the Volutes in clear 
shallow water in Magellan’s Straits, and, with the aid of natives, 
procured specimens—which nearly all grasped dead shells of 
Venus exalbida, a commor bivalve of that locality. Upon 
examining these shells they were found to contain within the 
cavity of one of the valves, a round, slightly convex mem- 
brane, comparable for size and transparency with a watch-glass. 
The contents appeared to be merely a milky fluid in some cases, 
but in others, the egg having advanced further in development, 
three or four small, but perfectly formed Volutes could be seen 
swimming in the fluid, which had becometransparent. D’Orbigny 
also collected large numbers of these eggs, and in the month of 
February saw the young Volutes, four or five in number, in each. 
The containing membrane, which becomes corneous, he describes 
as 80 to 100 millimetres in length, more than half the size of the 
animal which lays it, and he conjectures that it expands after 
coming into contact with the water. 
voLuTa (typical),Gray. Longitudinally plicate, plicee becoming 
prominent on the shoulder, columella with four or five principal 
plaits, and several smaller ones. Operculum (of V. musica) 
fusoid, narrowly elongated, with terminal nucleus. V. musica, 
Linn. (liii, 6). 
HARPULA, Swains. Shell oval-conic, spire with a papilliform 
but small summit ; columella with larger plaits below, and addi- 
tional smaller ones above, but less numerous than in the preceding 
section; exterior lip thickened within, sharp without. V7. ver- 
illum, Lam. (liii, 7). 
FULGORARIA, Schumacher, 1817. Shell oblong-fusiform ; spire 
