FAMILY TUREINID.E — TURRITELLA. 113 



TURRITELLA EROSA. 



PLATE VI. FIG. 122. 



(STATE COLLECTION.) 



Turritella erosa. Couthouy, Bost. Jour. Vol. 2, p. 103, pi. 3, fig. 1. 

 T. id. Godld, Invertebrata of Mass. p. 267. 



Description. Shell larger than the preceding, turreted, elongate. Whorls nine to eleven, 

 rather flat, smooth, sloping towards the suture : from three to five abruptly revolving grooves, 

 most prominent and numerous on the lower whorls. Striae of growth wrinkling the shell 

 longitudinally. Apex often eroded : aperture circular ; lip thin, and impressed by the termi- 

 nation of the costae. Columella with a slight callus and angular base. 



Color. Reddish brown ; epidermis sometimes dark lilac. 



Length, 0"5 - 0*8 ; of aperture, 0'15. 



Found in the stomachs of fishes, on the seacoast of Massachusetts. 



{EXTRA-LIMITAL.) 



T. impressa. (Say, Acad. Sc. Vol. 2, p. 244.) Shell with an acute apex : whorls six, with about four 

 acute impressed revolving lines ; lip not thickened, a slight indentation at its base, and a projection 

 within on the middle. Color, dusky. Length, 0*1. Seacoast. 



T. cequalis. (Say, Jour. Ac. Sc. Vol. 5, p. 208.) Shell subulate. Whorls ten, each with about twenty- 

 two transverse elevated obtuse equal lines, with interstitial grooves of the same diameter : suture 

 impressed, distinct ; aperture rounded at the base, and destitute of any distinct emargination. Color, 

 white. Length, 0.2. Seacoast. 



T. alternata. (Say, Ac. Sc. Vol. 2. p. 243.) Shell acute at apex. Whorls eight, with about eight 

 unequal revolving slightly elevated lines, maculated with rufous, and decussated by transverse ele- 

 vated obtuse lines, obsolete below the middle of the body-whorl, and prominent on the spire. Lip 

 not thickened ; a slight indentation at the base. Color, whitish ash. Animal with long white 

 tentacles, annulate with brown. Length, 0*2. Seacoast. 



T. concava. (Say, Ac. Sc. Vol. 5, p. 207.) Shell subulate. Whorls more than ten, concave in the 

 middle, and sculptured with 2-4 obsolete impressed revolving lines, and with an apicial and basal 

 band of about fifteen longitudinal undulations on each whorl ; the basal band passes round the 

 middle of the body whorl. Suture very slightly impressed: canal rather prominent South-Carolina. 



Fauna — Part 6. 1 5 



