92 



EAST COAST MARINE SHELLS 



SUBGENUS TECTONATICA Sacco 1890 



NATICA PUSILLA Say. A very small suboval 

 shell, sometimes with one to two faint 

 bands; callus pressed laterally into the 

 umbilicus which is almost closed. Length 

 6 mm. Range 2-15 fathoms. 



The smallest Floridlan Natica. 

 Often taken alive at Sanibel. 



PI 35, Fig. 11 



PI, 69, Fig. 21 



Casco Bay, Maine to Gulf of Mexico 



NATICA CLAUSA Brod. and Sby. Shell small, 

 tinged with brown; whorls four to five, su- 

 ture distinct; outer lip sharp, thickened; 

 interior white; operculum calcareous. 

 Length 16 mm. Depth range 16-1537 fathoms. 



PI. 42, Fig. 15 



Labrador to off North Carolina 



GENUS POLINICES Montfort 1810 



Shell generally smooth; umbillcate 

 or closed by a callus; operculum corneous. 



POLINICES BRUNNEA Link. Shell conic, deep- 

 ly umbilicated and with broad entering cal- 

 lus; color brownish or orange-broTm, base 

 and callus white. Length 30 mm. 



PI. 35, Fig. 2 



Palm Beach County to Florida Keys; 



Texas; West Indfes 



POLINICES LACTEA Guilding. Shell ovate; 

 epidermis when present thin and yellowish; 

 umbilicus of moderate size, partly filled 

 with entering callus. Length 1 inch. 



It lives In Lake Worth, Florida. 

 The normal operculum is yellowish but occa- 

 sionally claret colored. 



PI. S5, Fig, 15 



Palm Beach to Florida Keys; Texas, 



West Indies 



SUBGENUS NEVERITA Risso 1826 



Operculum simple, corneous. 



POLINICES DUPLICATA Say. Shell solid, 

 ovate, compressed above so as to give a 

 pyramidal outline; whorls five or more; 

 spire rather prominent; aperture ovate, very 

 oblique; lip thin and sharp; callus upon 

 the parietal wall very heavy and wide; in- 

 terior generally of a pearly lustre; umbil- 

 icus deeply grooved inside. Length 2 inches. 



breadth slightly more. 

 PI. 35, Fig. 9 

 PI. 70, Fig. 12 

 Massachusetts Bay to Gulf of Mexico 



SUBGENUS EUSPIRA Agassiz in Sowerby 1838; 

 Lunatia Gray 1847 



POLINICES HERDS Say. Shell globose-ovate, 

 thick ash-colored, shining when epidermis 

 is removed; growth lines distinct; whorls 

 five, very convex; suture well marked; 

 aperture ovate, lip sharp above, gradually 

 rounded, thickened and expanded near the 

 umbilicus; thin layer of enamel upon parie- 

 tal wall; umbilicus large, round and show- 

 ing the whorls to summit; operculum horny. 

 Average length 2.5 inches, breadth 2 inch- 

 es. 



A voracious mollusk which devours 

 dead fish. It plows through the sand, a 

 little below the surface, the position 

 often being indicated by a heap of sand at 

 the end of a trail. 



The eggs are deposited in clusters 

 which in shape and thickness resemble an 

 orange peel, easily bent without breaking 

 when damp. When held up to the light the 

 individual cells may clearly be seen. Each 

 of these contains a gelatinous egg, with a 

 yellow nucleus which is the embryo shell. 

 Range 0-238 fathoms. Animal PI. 70, Fig.l. 

 PI. 35, Fig. 14 

 PI. 70, Fig. 11 



Gulf of St. Lawrence to North Caro- 

 lina 



POLINICES TRISERIATA Say. Whorls five, 

 usually with three series of dark spots on 

 lower whorl, one on upper ones; umbilicus 

 quite small, almost free; color yellowish 

 white, epidermis also yellowish. Length 

 17 mm. 



An ivory-white callus is the most 

 constant character. It is a variable form 

 found on mud flats at low tide. Range 1-63 

 fathoms. The early stages of growth are 

 shown on PI. 69. 



PI. 35, Fig. 8 

 PI. 69, Figs. 18, 19 

 Gulf of St. Lawrence to North Caro- 

 lina 



POLINICES GROENLANDICA Moller. Shell sub- 

 oval, ash colored; umbilicus partially cov- 

 ered; surface glossy; spiral lines micro- 

 scopic; whorls four, convex; suture deep; 



