EAST COAST MARINE SHELLS 



105 



groove; final whorl smaller than the previ- 

 ous one; aperture very small; two canals 

 which are open only at ends. Length 6 mm. 



PI. 38, Fig. 5 



PI. 65, Fig. 6 



North Carolina to the West Indies 



Family Cerithlopsidae 



Shell small, cylindrical, narrow, 

 not varicose; whorls numerous; aperture 

 small, canal almost straight. Mostly liv- 

 ing in temperate seas. 



GENUS CERITHIOPSIS Forbes and Hanley 1829 



CERITHIOPSIS GREENII Adams. Shell small, 

 reddish black; whorls ten to twelve; last 

 whorl with twenty to twenty-five folds or 

 ridges; canal slightly turned, short and 

 deep. Length 5 mm. 



It lives upon marine plants, short- 

 ly below low-tide mark. Compared to the 

 similar Bittium alternatum the shell bulges 

 more, the whorls extend out and the canal is 

 more impressed. It is also a smaller shell 

 but the color is very similar. 



PI. 38, Fig. 6 



PI. 71, Fig. 2 



Massachusetts Bay to the West Indies 



CERITHIOPSIS VIRGINICA Henderson and 

 Bartsch, Shell minute, brown except for 

 yellowish apex; sixteen to eighteen strong 

 axial ribs and three strong spiral cords on 

 each whorl, forming tubercles where ribs 

 and cords Join; rectangular pits between 

 ribs and cords on all except last whorl 

 where they are rounded; periphery of last 

 whorl keeled; two spiral cords on base, out- 

 er lip thin. Length 2.9 mm., diameter 1 mm. 



It was dredged in Virginia on eel- 

 ^rass. 



PI. 38, Fig, 23 



Bay at Chincoteague, Virginia; Mary^ 



land 



SECTION METAXIA Monterosato 1884 



CERITHIOPSIS METAXAE Delia Chiaje. Whorls 

 narrow, convex; nodules placed so that 

 longitudinal ribs are visible; three spiral 

 series of nodules on the upper and four on 

 lower whorls; last whorl keeled at periph- 

 ery, base smooth; lip cut out at base. Col- 

 or varying from light brown to red. Length 

 8 mm. Range 2-220 fathoms. 



This little shell also lives in the 

 Pacific and upon European shores. 

 PI. 38, Fig. 1 

 North Carolina to the West Indies 



SUBGENUS LASKEYA Iredale 1918 



CERITHIOPSIS SUBULATA Montagu (C. emersonii 

 C. B. Adams). Light or brown, usually dark- 

 er at suture; whorls flat and divided into 

 three rows of granules by spiral sculpture, 

 the middle row less prominent; suture deep- 

 ly grooved; base smooth with cord-like 

 ridges. Length 12 mm. Depth 2-15 fathoms. 



PI. 38, Fig. 2 



PI. 71, Fig. 1 



Massachusetts to the West Indies 



GENUS SEILA A. Adams 1861 



SEILA ADAMSII H. C. Lea (C. terebrans 

 C. B. A.). Ten flat whorls with sharp ele- 

 vated ridges; base short, smooth, bounded 

 by a ridge; color chocolate brown or yel- 

 lowish. Length 10 mm. 



This shell was taken by the author 

 under sponges at Ligniim Vitae Key, Florida, 

 in shallow water. Dead examples may be 

 found almost everywhere among minute shells. 



PI. 38, Fig. 22 



PI. 71, Fig. 5 



Massachusetts to Florida 



Family Cerithiidae 



Shell elongated, many whorled, 

 often varicose; aperture channelled in 

 front with an Inconspicuous posterior canal; 

 operculum horny and spiral. 



GENUS CERITHIUM Bruguiere 1789 

 (HERALD'S HORN) 



Shell turreted, varices not pro- 

 nounced; aperture small. 



CERITHIUM ALGICOLA C. B. Adams. Centers of 

 whorls angulated; longitudinal ribs with 

 more or less sharp knobs where they cross 

 the angle; fine revolving raised threads 

 covering surface; aperture rounded; columel- 

 la concave; color white variegated with yel- 

 low. Length 20 mm. 



PI. 38, Fig. 10 



Southern Florida and West Indies 



