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158 Base of shell with 2 large, smoothish, spiral cords. C. grippi Bartsch and C. pedroana Bartsch are possibly dwarf forms of this species whose beaded sculpture is more variable than is generally suspected. Genus Seila A. Adams 1861 Shell small, very slender, whorls flat-sided, nucleus glassy-smooth and of about 3 whorls. Small, short siphonal canal. Sculpture of strong spiral cords between which lie microscopic axial threads. Seila adamsi H. C. Lea Adams' Miniature Cerith Plate 2 2t Massachusetts to Florida, Texas and the West Indies. /4 to /4 inch in length, resembling a miniature Terebra, with about a dozen whorls. Long, slender, flat-sided, dark-brown to light orange-brown in color, and characterized by 3 strong, squarish, spiral cords on each whorl (4 on the last whorl). Occasionally with minute axial threads showing be- tween the spiral cords. Base of shell smoothish, concave. Outer Hp fragile, wavy and sharp. Suture indistinct. This is S. terebralis C. B. Adams. Common from shore to 40 fathoms. Seila monterey ensis Bartsch Monterey Miniature Cerith Monterey, California, to the Gulf of California. % to /4 inch in length, yellowish to reddish brown. Whorls and spire flat-sided. Whorls in spire with 3 raised, flat-topped, evenly spaced, smooth cords between which are numerous, microscopic, axial threads. Last whorl with 5 cords. Base smoothish, concave. Common from low tide to 35 fathoms. Genus Alabma Dall 1902 Shell small, slender. Nucleus slender, of 3 to 4 glassy, smooth whorls. Aperture subcircular. Lower part of the outer lip extended and flaring. Umbilicus very narrow and very small. With obscure, narrow, curved axial ribs and prominent spiral threads. This genus is put in the family Diastomidae by some workers. Alabifia tenuisculpta Carpenter Sculptured Alabine San Pedro, California, to Lower California. /4 inch in length, slender, 8 to 9 whorls, ashen gray with a light-brown undertone. Outer lip thin; umbilicus small. Spiral sculpture of 4 to 6 weak