224 BELOMITRA, LACHESIS. 
B. aura, Montagu. PI. 32, fig. 35. 
Whorls seven, rather convex, very slightly shouldered ; ribs 
14 or 15, narrower than the interstices ; surface covered with fine 
close revolving striz ; chocolate-brown, the ribs lighter colored. 
Length, 13 mill. 
Hurope. 
The synonymy is enormous, including B. Kieneri, Marav., B. 
chordula, Turton (juv.), B. nigra, Potiez et Mich., B. fusca, B. 
discors, B. castanea and B. discrepans of Brown, and perhaps 
also B. alba and B. minima of the same author. 
Jeffreys distinguishes the following varieties :— 
Var. LAcTEA. Shell white. 
Var. sEMicostaTA. Lower whoris ribless ; shell often larger. 
Var. UHLIDEANA, Thompson. Shell orange-brown or fawn-color, 
with stronger sculpture. 
Var. CrAncuHII, Brown. Ribs twisted. 
Var. ANausTA. Shell narrower, and slender, with sharp and 
oblique ribs. 
Subgenus BeEtomitra, Fischer, 1882. 
B. PARADOXA. Fischer. 
Shell elongately fusiform, whitish, whorls eight, the embryonal 
obtuse, mammillate, the others slightly convex, angulately cari- 
nated in the middle, with about twelve subarcuate longitudinal 
ribs, which become evanescent below the middle of the body- 
whorl, and revolving strive; aperture oblong, narrow; lip obso- 
letely sinuous behind, smooth within ; columella nearly vertical 
with six or seven oblique narrow plications ; canal short. 
L. 28, diam. 9; L. apert. 14 mill. 
Atlantic, 627 metres. 
Locality not given. Unfigured. 
Genus LACHESIS, Risso, 1826. 
L. mintMA, Montagu. PI. 32, figs. 21,24; Pl. 27, fig. 4. 
Shell solid, opaque, rather glossy ; ribs nine or ten, crossed by 
fifteen to twenty broad, flattened spiral ridges on the body-whorl, 
four on the spire whorls; apex globular, twisted on one side ; 
whorls five to six, rather convex; outer lip varicose without, 
