download pdf

240 American Seashells
Nassarius mendicus Gould Western Lean Nassa
Alaska to Lower California.
Figure 53d
% to % inch in length, with a moderately high spire. Outer lip not
thickened. Sculpture consists of numerous, small beads which are formed by
the crossing of about a dozen small axial ribs and smaller spiral threads. Color
yellowish gray. Common in shallow water in the north.
The subspecies or form cooperi Forbes has weaker spiral threads and
about 7 to 9 strong, whitish, smoother axial ribs which persist to the last of
the body whorl. Color grayish yellow to whitish, often with fine, spiral,
brown or mauve lines. Very common in the south.
Nassarius fossatus Gould ^
Subgenus Zaphon H. and A. Adams 1853
Vancouver Island to Lower California.
Giant Western Nassa
Plate 20s
I V2 to 2 inches in length, orange-brown to brownish white in color.
Early whorls coarsely beaded; last whorl with about a dozen coarse, variously
sized, flat-topped spiral threads and with about a dozen short axial ribs on the
top third of the last whorl. Outer lip with a jagged edge and constricted
at the top. The largest and one of the common intertidal Nassa snails on the
Pacific coast.
Subgenus llyanassa Stimpson 1865
Nassarius obsoletus Say Eastern Mud Nassa
Plate 23P
Gulf of St. Lawrence to northeast Florida. Introduced to the Pacific
coast.
/4 to I inch in length, usually covered with mud and algae, and has its
spire eroded at the tip. Color dark black-brown. Sculpture of numerous
rows of weak beads. Parietal wall thickly glazed with brown and gray.
Columella with a single, strong spiral ridge near the base. Outer lip with half
a dozen small grayish teeth which run back into the aperture. Very common
on oozy, warm mud flats.
Family FASCIOLARllDAE
Subfamily FASCIOLARIINAE
Genus Leucozonia Gray 1847
Leucozonia nassa Gmelin Chestnut Latirus
Florida to Texas and the West Indies.
Plate 1 1 1!