446 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Nerita tessellata Gmelin. 
Neritci tessellata Gmelin, Syst. Nat., p.3685, 1792. 
Nerita tessellata Reeve, Conch. Icon., ix, pl.ix, figs. 43, 43a, 1855. 
Shell with rather low bluntly pointed spire and from three to three and a half whorls which are 
scarcely convex, the last flattened or a little concave above; the sculpture consists of strong, rounded 
ridges throughout; lip thick, grooved within, with two teeth above; columellar area excavated pustulous; 
outline of columella somewhat incurved, with one or two faint teeth in middle. Color white, tessel- 
lated with black. Sometimes the entire shell is black, with a few white markings; interior bluish. 
Height, 20; diameter, 17 mm. 
This abundant species was taken at thirteen different stations about Porto Rico; West Indies; 
Florida Keys. 
Nerita tessellata var. prsecognita C. B. Adams. 
Nerita pnecognita Reeve, Conch. Icon.,ix, pl.vn, figs. 30a, 30b, 1855. 
In the variety the spire is generally lower than in the type, the columella is straighter and more 
strongly toothed, and the area is less excavated. 
Height, 20; diameter, 23 mm. 
Culebra, four shells. 
Nerita versicolor Lamarck. 
Nerita versicolor Lamarck, An. sans Vert., vi, p. 193, 1882. 
Nerita versicolor Reeve, Conch. Icon., ix, pl.xn, figs, 56, a. b, c, d, 1855. 
Shell with a somewhat elevated, pointed spire, the last whorl slightly concave below the suture; 
sculptured with strong, revolving ridges throughout; aperture crescentic; lip within with one strong 
tooth above and one below, with a row of smaller ones between; columellar area full or flat, wrinkles, 
which are slightly pustulous; columella convex, with four strong teeth. Color of the ground whitish, 
often brilliantly tinted with red; ribs marked with square or elongated violet or black spots. 
Height, 20; diameter 17 mm. 
Found abundantly at nearly all the stations around Porto Rico. 
Genus NERITINA Lamarck, 1809. 
Shell relatively thin, subglobose or oval, whorls generally smooth, sometimes rough or spinose; 
aperture semicircular; columellar border straight, finely toothed or smooth; lip sharp, not toothed or 
ridged within; operculum shelly, with a flexible border, exhibiting two processes which have been 
called a rib and a peg. 
-Neritina reclivata Say. 
Neritina reclivata Say , Journ. Acad. Nat. Sci. Phila., in, 1822, p. 257. 
Neritina reclivata Tryon, Man.., x, p. 39, pi. xn, figs. 25-30, 1888. 
Shell globosely conical; spire somewhat produced but obtuse; whorls concavely slanting on the 
shoulder; suture well defined; aperture semilunar, patulous; inner lip nearly straight, faintly toothed 
in the middle. Color olivaceous, greenish, or brownish, with oblique, undulating dark lines which are 
sometimes reticulated. Height, 20; diameter, 7 mm. Vieques, one worn shell. 
Neritina virginea Linnaeus. 
Nerita virginea Linnaeus, Syst. Nat., ed. x, p. 778, 1758. 
Neritina virginea Reeve, Conch. Icon., ix.pl. xxi, fig. 92, a to d. 1855. 
Shell smooth, polished, usually white, sage colored, yellowish, or violaceous, with a fine, close 
pattern of parallel, longitudinal darker or lighter lines; these sometimes are reticulated, or give the 
markings the appearance of scales on a fish. The shell may be variously spotted or zoned; in fact there 
is an endless variety in coloring. The spire is generally low or only moderately developed and obtuse; 
the whorls below the suture are usually a little sloped, the lip is sharp, the columella is straight, with 
a number of rather strong teeth. 
Diameter, from 6 to 20 mm.; height about the same as the diameter, sometimes a little greater. 
San Juan; Mayaguez, Porto Rico; a number of shells. 
Neritina viridis Linnaeus. 
Nerita viridis Linnaeus, Syst. Nat., ed. x, p. 778, 1758. 
Neritina ( Smaragdia ) viridis Tryon, Man., x, p. 54, pi. xvnr, fig. 88, 1888. 
Mayaguez, Porto Rico, one dead specimen. 
