274 MOLLUSCA. 
SHELL quite small, polished, shining, elongated, ovate-fusiform, very 
deep mahogany-brown colour, beautifully variegated with numerous, 
delicate, obliquely flexuous, yellowish, longitudinal stripes, destitute of 
sculpture except three or four raised threads about the beak; whorls 
seven, slightly convex, the last nearly three-fourths the length of the 
shell, tapering downwards about equally with the spire; suture linear, 
impressed. Aperture half the length of the shell, quite narrow ellip- 
tical; lip simple; columella with three folds, the upper of which is 
largest, and with a deposit of callus at the posterior angle; colour of 
the interior lurid. 
Length nine-twentieths of an inch; breadth one-fifth of an inch. 
Inhabits the Madeira Islands. Couwthouy. 
This beautiful little shell is easily identified by its dark mahogany 
colour, and its delicate yellow lineations, like those on some species of 
Neritina. MW. semen, Reeve, which is not so slender, and has fewer 
and broader lines, is the only species approaching it. 
Mirra ENCAuSTA (Gould). 
T. parvula, sohda, curta, ovato-rhomboidea, cinerea, longitrorsum octo 
ad novem-plicata et sulcis fuscescentibus cincta: spira conica, anfrac- 
tibus octo ventricosis, supernis granulosis, ultimo trientes duos longt- 
tudinis teste adequante; sutura canaliculatd: apertura parva, line- 
aris; labro acuto, viz sulcato; columella plicata, posticé callo copioso 
induta. 
Mitra encausta, Goutp; Proceed. Boston Soc. Nat. Hist., iii. 172. 
January 1850. Expedition Shells, 73. 
SHELL quite small and solid, short, rhomboid-ovate, about equally 
acuminated each way, ash-coloured, with eight or nine coarse longitu- 
dinal folds, and with deeply incised, regularly spaced, revolving strie 
of a dusky colour, about four on the whorls of the spire, rendering 
the upper ones granular, more distant and coarser at base, where the 
raised portions are granular. Whorls eight, ventricose, with a some- 
what channeled suture; the last whorl two-thirds the length of the 
