MARINE MOLLUSCA OF THE UNITED STATES. 63 
thin and fragile; pillar lip flattened, and with a small superficial 
fold. Epidermis whitish or reddish-brown, with numerous bands 
of brown; pillar white. 
Length 10, diam. 12.5 mill. 
Generally covered with a calcareous incrustation ; underneath 
zoned or frequently entirely white or flesh color. 
Coralline, on stones, dredged in 14 to 40 fathoms. 
Massachusetts northwards (Eur.). 
Family PYRAMIDELLID. 
The animal, in this family, is provided with broad, ear-shaped 
tentacles which are often connate, with eyes behind them at their 
bases; proboscis retractile; foot truncated in front; the tongue 
unarmed. 
Synopsis of Genera. 
Shell subulate, turreted, many-whorled, smooth; spire pointed, nucleus 
sinistral; aperture semi-oval, entire, rounded anteriorly; columella 
straight, plicated; outer lip acute. OBELIscus, Humphrey. 
Shell slender, elongated, many-whorled, longitudinally ribbed; apex of 
spire with a persistent, embryonic, sinistral nucleus; aperture oblong or 
subquadrate, peristome incomplete; columella straight, simple, edentulate 
and without a plait. TURBONILLA, Risso. 
Shell turreted, subulate or ovate, smooth or transversely striated ; apex of 
spire sinistral; aperture ovate, peristome not continuous; columellar lip 
with a single tooth-like fold. Opostomia, Fleming. 
Shell turreted, many-whorled, whorls smooth or spirally striated; aperture 
oval or rounded; inner lip simple, without plaits or teeth, base often per- 
forated. Acuis, Lovén. 
Shell elongated, imperforate, many-whorled, transversely striated; aperture 
small, ovate, entire in front ; columellar lip smooth or obscurely plaited. 
MENESTHO, Moller. 
Shell elongated, white, smooth, polished; spire produced, many-whorled, 
frequently with an interrupted varix on one side, apex acute; aperture 
oval, pointed behind; inner lip reflected over the pillar; axis imperforated ; 
outer lip thickened internally. . Euuma, Risso. 
Shell subulate or subglobose, thin, pellucid, smooth, polished, many- 
whorled ; apex of spire produced and styliform, with a sinistral nucleus ; 
aperture sub-ovate, pointed behind, rounded and entire in front; inner lip 
smooth, arcuated ; outer lip thin, simple. StyLiFER, Broderip. 
