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Rh 2 yellowish white, swollen varices on the spire. A very common species found in large colonies on mud flats.

Figure 39. Last whorl and opercula in the Horn Shells. (From J. Bequaert in Johusoina.) Subfamily BATILLARIINAE Genus Batillaria Benson 1842 Cerithium-like in appearance. Siphonal canal very short and twisted to the left. Outer lip smooth inside. Operculum round, multispiral and horny, while in Cerithidea and Cerithium it is paucispiral. Batillaria mi7iima Gmelin South half of Florida and the West Indies. False Cerith Plate 19s V2 to % inch in length, resembling the Dwarf Cerith, C. variabile (see below). Color varies from black, gray to whitish, and often has black or white spiral lines. Finely nodulose with coarse axial swellings and uneven spiral threads. The siphonal canal is very short and twisted slightly to the left. Operculum multispiral. A very common intertidal species. Percy Morris (i95i» pl- 31^ %• 15) labels this species as Cerithidea turrita. Family CERITHIIDAE Genus Cerithium Bruguiere 1789 Thericium Monterosato is this genus. The operculum is horny, thin, brown and paucispiral. Most species in the genus are shallow-water dwellers. Cerithium floridanum Morch North Carolina to the south half of Florida. Florida Cerith Plate 1911 I to 1V2 inches in length, elongate. Spire pointed, with 2 or 3 white, former varices on each whorl. Siphonal canal well-developed. With several spiral rows of 18 to 20 neat beads per whorl between which are fine, granu- lated spiral threads. Color whitish with mottlings and specklings of reddish brown. Distinguished from C. literatimi by its more elongate shape and neater, smaller, more numerous beads. Common in shallow water.