D. Rather globose, h/d ratio 75; shore to 50 fms.; southeast Florida
parvicallum Pils. and McG.
DD. Depressed, h/d ratio about 50:
E. Callus large. Lake Worth
obtectum Pils. and McG.
EE. Callus small. Biscayne Bay, shore
biscaynense Pils. and McG.
CC. Diameter 0.7 to 1.0 mm.; callus thick; Lower Keys, shore
leremum Pils. and McG.
Superfamily Cerithiacea Family Turretellidae GenusTachyrhynchusMorch 1868
Tachyrhynchus erostum Couthouy
Eroded Turret-shell Plate 21l
Nova Scotia to Cape Cod, Massachusetts. Alaska to British Columbia.
3⁄4 to 1 inch in length, elongate, 1⁄4 as wide; 8 to 10 rounded whorls. No umbilicus. Aperture round; columella smooth, slightly arched. Whorls with 5 to 6 smooth, flat-topped, spiral cords between sutures. Color cream to chalky-white, with a thin, polished, gray-brown periostracum. Operculum round, multispiral, chitinous, dark-brown. Common from 10 to 75 fathoms.
T. reticulatum Mighels (Arctic Ocean to Maine; and Alaska) is similar,