154 American Seashells 



Cerithium muscarum Say Fly-specked Cerith 



Plate 19m 



South half of Florida and the West Indies. 



I inch in length, moderately elongate. Siphonal canal rather long and 

 twisted to the left. 9 to 1 1 nodulated axial ribs on each whorl. Base of shell 

 with a very strong spiral cord, often nodulated. Former varices rarely pres- 

 ent. Apertural side of body whorl convex. Color slate- to brown-gray, 

 usually with brown to reddish specks in spiral rows. Common in shallow, 

 warm waters on the west coast of Florida. 



Cerithium literatiim Born Stocky Cerith 



Plate 19I 



Southeast Florida, Bermuda and the West Indies. 



I inch in length, half as wide; siphonal canal short. Aperture side of 

 body whorl slightly flattened. Usually i weak, former varix present. With 

 numerous coarse spiral threads, and with a spiral row of 9 to 12 sharp, promi- 

 nent nodules just below the suture. Sometimes a second, smaller row of 

 spines is on the periphery. Color whitish with spiral rows of many black 

 or reddish squares. Common in shallow water on the Lower Florida Keys. 



Cerithium ebiirneum Bruguiere Ivory Cerith 



Plate i9q 



Southeast Florida, the Bahamas and Greater Antilles. 



% to I (rarely iK>) inches in length, variable in shape, but usually 

 moderately elongate. Each whorl has 4 to 6 spiral rows of from 1 8 to 2 2 small 

 rounded beads. The beads are slightly larger in the middle row. There are 

 usually a number of fairly large, former varices. Color variable: all white or 

 cream, or with reddish brown blotches. Very common in shallow water. 

 C. versicolor C. B. Adams is this species. Compare with algicola which may 

 ultimately prove to be a genetic form of this species. 



Cerithiwn algicola C. B. Adams Middle-spined Cerith 



Plate I9P 



Southern third of Florida and the West Indies. 



I inch in length, similar to eburneum, but characterized by each whorl 

 having the middle spiral row of 9 to 12 beads fairly large and pointed. These 

 large beads may be axially drawn out to form low ribs. Former varices are 

 not often present. Color as in ehumewn. Common in the West Indies. C. 

 liter atum has its strongest row of spine-like beads just below the suture. 



Certthiu7n variabile C. B. Adams Dwarf Cerith 



Plate 19-0 



South half of Florida to Texas and the West Indies. 



