FAMILY TURBINIDZ — NATICA. 121 
NaTICA DUPLICATA. 
PLATE VII. FIG. 147. 
(STATE COLLECTION.) 
Natica duplicata. Say, Journ, Acad. Nat. Sciences, Vol. 2, p. 247. 
N. id. GouLp, Invertebrata of Mass. p. 236, fig. 164. 
Description. Shell solid, subglobular. Whorls five ; the upper whorls not very convex, 
marked by the lines of growth: aperture oval, oblique; umbilicus irregular, with a deep 
furrow, and almost entirely covered by a thick callus. 
Color. Ashen, with a dark line or band revolving around the spire above the suture, 
becoming gradually obsolete ; within, deep chesnut-brown: callus of the same color. 
Length, 1:0 -2°0. Diameter, 1°0 - 271. 
This is one of the most common species on the coast. 
NAaTICA TRISERIATA. 
PLATE VII. FIG. 144 
(STATE COLLECTION.) 
Natica triseriata. Say, Journ. Acad. Nat. Sciences, Vol. 5, p. 209. 
N. td. Goutp, Invertebrata of Mass. p. 233, fig. 165. 
Description. Shell longitudinally suboval, nearly globular. Whorls five, convex: spire 
somewhat elevated ; suture slightly impressed ; aperture ovate ; lip simple, acute ; pillar-lip 
with a thick callus, slightly modifying the umbilicus, which is open, rounded. 
Color. Epidermis thin, yellowish: three revolving series of large oblique parallel oblong 
dark reddish brown spots, about twelve or fourteen in each series; the upper series most 
usually found on all the whorls: these series are more or less distinctly exhibited within the 
aperture. 
Length, 0°4-0°6. Width, 0°3-0°5. 
This species appears to be very common north of Cape Cod. I have obtained a few 
specimens from the east end of Long island. 
Fauna — Part 6. 16 
