VOLUTID^. 103 



seas of Europe, although they were numerous during the tertiary 

 epoch ; V. abi/ssicola^ 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 Yolutes, 

 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 ; Europe, Asia, N. America. V. musica, Linn, 

 (liii, 6). 



Shell ovate or subconical, thick, solid ; spire usually short ; 

 shoulder of whorls usuall}' 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 Yolutes 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 common bivalve of that localit}'. 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 Yolutes could be seen 

 swimming in the fluid, which had become transparent. D 'Orbigny 

 also collected large numbers of these eggs, and in the month of 

 February saw the young Yolutes, 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 laj's it, and he conjectures that it expands after 

 coming into contact with the water. 



VOLUTA (typical). Gray. Longitudinally plicate, plicse 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. V. vex- 

 illum, Lam. (liii, '7). 



FULGORARiA, Schumacher, 1817. Shell oblong-fusiform ; spire 



