90 



EAST COAST MARINE SHELLS 



This very distinct and attractive 

 shell has been taken at Sanlbel, Florida. 

 In Charlotte Harbor it has been dredged in 

 2 fathoms. At Key West it has been col- 

 lected between tides. 



PI. 34, Fig. 2S 



West Florida to Key West 



GENUS OSCILLA A. Adams 1867 



OSCILLA BISERIATA Gabb (T. nivea Morch) . 

 Shell white, slender, three spiral ribs on 

 each of the flattened whorls; two plain 

 ribs below the nodulous ones on body whorl; 

 three encircling ridges beneath the periph- 

 ery forming folds on columella; about twen- 

 ty-one nodules upon circuit of last whorl; 

 nucleus glassy, rounded. Length 8.5 mm. 



A single specimen was dredged by 

 the author on Featherbed Bank, Card Sound, 

 Florida. Fresh examples occurred in drift 

 taken near the Shark Factory on Big Pine 

 Key, Florida. 



PI. 33, Fig. 13 



PI. 68, Fig. g 



Card Sound to Key West, Florida 



GENUS ODOSTOMIA Fleming 1817 



Few whorled, minute, usually short 

 shells; columella fold single, outer lip 

 entire. In Florida they may be sought for 

 under oyster shells. 



ODOSTOMIA IMPRESSA Say. "Shell elongate, 

 conic, milk white; nuclear whorls small, 

 about half immersed in first succeeding 

 turns; postnuclear turns flattened, shoul- 

 dered above, marked by three strong deeply 

 cut spiral grooves, the grooves cut by spi- 

 ral threads; spaces between spiral grooves 

 rounded on sides and obliquely flattened on 

 top; sutures channelled, periphery marked 

 by deep channel, like those above it; base 

 well rounded marked by seven spiral grooves 

 like spaces between sutures; outer lip thin, 

 slightly sinuous at edge, showing external 

 scxilpture within; columella very stout with 

 strong oblique fold at insertion." Bartsch. 

 Length 4.8 mm. 



PI. 34, Fig. 16 



PI. 71, Fig. 11 



Massachusetts Bay to Gulf of Mexico 



ODOSTOMIA SEMINUDA C. B. Adams. "Shell very 

 elongate-ovate, milk white, at least two 

 nuclear whorls; postnuclear whorls well 



rounded, somewhat shouldered at summit; 

 nodular axial ribs increasing from eighteen 

 upon second to twenty-four upon the fourth 

 and penultimate whorl; also four low spiral 

 ridges which divide the space between su- 

 tures into four equal areas; spaces between 

 spiral ridges about one-sixth as wide as 

 ridges. The nodules are formed by the Junc- 

 tion of the spirals and axial ribs; sutures 

 channelled; base of last whorl with about 

 seven incised spiral grooves; aperture ir- 

 regular, ear-shaped; outer lip thick inside 

 but edge thin; columella strong, twisted 

 and reflexed, provided with oblique fold." 

 Length 3.8 mm. 



PI. 34, Fig. 17 



PI. 71, Fig. 10 



Prince Edward Island to Gulf of 



Mexico 



ODOSTOMIA TRIFIDA Totten. "Shell elongate- 

 ovate, shining white; nuclear whorls small, 

 almost immersed in the first of the succeed- 

 ing turns; postnuclear whorls almost flat- 

 tened, sho\ildered at summit, crossed by 

 three deeply cut spiral lines and a ■ faint 

 one; these channels crossed by weak axial 

 threads; sutures faintly Impressed; base 

 rounded, marked by about ten feebly cut 

 spiral lines which are irregular in strength 

 and spacing; outer lip thin, showing ex- 

 ternal sculpture within; columella short, 

 with strong oblique fold at insertion; sev- 

 en postnuclear whorls." Length 4 mm. 



PI. 34, Fig. 14; PI. 71, Fig. 8 



Maine to New Jersey 



ODOSTOMIA BISUTURALIS Say. "Shell conic, 

 milk white; nuclear whorls at least two, 

 more than half immersed in the succeeding 

 turns; postnuclear whorls moderately round- 

 ed, somewhat shouldered at summit; spiral- 

 ly marked by a deeply incised channel a 

 short distance above the summits of the 

 whorls; deep channel crossed by many fine 

 axial threads; aperture large; outer lip 

 thin, columella slender, strongly reflexed, 

 with an oblique fold at insertion which is 

 not visible when aperture is viewed square- 

 ly; whorls eight postnuclear." Length 4.7 

 mm. Range 1-2 fathoms. 



PI. 34, Fig. 19 



PI. 71, Fig. 7 



Gulf of St. Lawrence to Delaware 



Bay. 



ODOSTOMIA BISUTURALIS OVILENSIS Bartsch. 



