CERITHIIDAE 155 



% to /4 inch in length, not elongate. Apertural side of body whorl 

 sometimes flat, i to 2 former varices on last whorl. 3 or 4 spiral rows of 

 even-sized fine beads on the whorls of the spire. Color dark brown-black, 

 but sometimes whitish with heavy specklings and mottlings and bands of 

 reddish brown. Very common under rocks in warm water. Do not confuse 

 with Batillaria ininwia (see above). 



Genus Bittium Gray 1847 



Shell small, very slender, spire high and body whorl small. Whorls 

 varicose. Nucleus of about 3 glassy, smooth whorls. Aperture ovate, the 

 anterior canal broad and stout. 



Subgenus Bittiwn s. str. 

 Bittiu?7i altematiim Say Alternate Bittium 



Gulf of St. Lawrence to Virginia. 



Adults very small, % to /4 inch in length, light- to dark-brown in color, 

 sometimes translucent or with specklings. Suture impressed, whorls rounded. 

 Sculpture on top whorls either cancellate or with 4 to 5 spiral rows of beads, 

 or occasionally with axial, nodulated ribs. Base with small spiral cords. Outer 

 lip flaring, thin and sharp. Columella short, twisted at the base and stained 

 brown. Very abundant from tidal flats to 20 fathoms. 



B. virginicuffi Henderson and Bartsch from Chincoteague, Virginia, is 

 similar, but very elongate, more whorls, with a much more flaring and basally 

 projecting lip, and with a large, whitish, former varix on the body whorl. 



Bittium variimt Pfeiffer Variable Bittium 



Plate 191 

 Maryland to Florida, Texas and Mexico. 



Adults similar to altematiim, but smaller (% inch), nearly always with 

 a former, thickened varix. The aperture is proportionately smaller and the 

 base of the apertural lip is squarish instead of rounded. The last third of the 

 body whorl is generally destitute of sculpturing. Common in eel-grass just 

 below low tide. 



Subgenus Stylidium Dall 1907 

 Bittium eschrichti Middendorf Giant Pacific Coast Bittium 



Alaska to Crescent City, California. 



