download pdf

460 American Seash ells
in soft coral rocks. Erroneously called c7meifor77iis Spengler which is an
Indo-Pacific species (see E. Lamy, 1924).
Rocellaria ovata Sowerby (Bermuda and the Atlantic Coast, rare) is
very similar, but the beaks are at the very end of the valve, and the shell is
more elongate. In hians, there is a very small, wing-like projection of the
valve in front of the beak.
Genus Spengleria Tryon 1861
Similar to Rocellaria, but truncate at the posterior end where there are
strong, concentric ribs. Beaks at the anterior third of the shell.
Spengleria rostrata Spengler Atlantic Spengler Clam
Southeast Florida and the West Indies.
I inch in length; valve truncate at the posterior end. There is a very
characteristic, elevated, triangular area which radiates from the beaks to the
large, posterior end. This area is crossed by strong, transverse lamellations
resembling a washboard. Commonly found boring in soft coral rock. Uncommon
in Florida.
Superfamily ADESMACEA
Family PHOLADIDAE
Pending publication of the extensive researches on this group by Dr.
Ruth D, Turner at Harvard University, we are dividing the groups in this
family and treating the species in the conventional manner.
Genus Cyrtopleiira Tryon 1862
Barnea costata Linne Angel Wing
Massachusetts to Florida, Texas and the West Indies.
Figure 94a
4 to 8 inches in length, moderately fragile; pure white in color, but in
life covered by a thin, gray periostracum. With about 30 well-developed,
beaded radial ribs which are scale-like at the anterior end of the valve. In
fresh material, there is a shelly accessory plate over the hinge area. It is
somewhat triangular and with complicated furrows. The internal brace
under the beaks is spoon-shaped and with a narrow, strongly hooked at-
tached end. Common in sticky mud about a foot under the surface (con-
sult "Diggin' 'Em Out" by B. R. Bales, The Nautilus, vol. 59, pp. 13 to 17).
Some colonies have shells which have pink, concentric stains on the inside of