MARINE MOLLUSCA OF THE UNITED STATES. 13 
Shell at first discoidal, becoming decollated when adult ; tubular, cylindri- 
cal, arched; aperture round, entire; apex closed by a mammillated 
septum ; operculum horny, many-whorled. Cacum, Fleming. 
Shell mostly pure white and lustrous; turreted; many-whorled ; whorls 
round, sometimes separate, ornamented with numerous transverse ribs ; 
aperture round ; peristome continuous ; operculum horny, few-whorled. 
ScaLariA, Lamarck. 
Genus TURRITELLA, Lamarck. 
Prodr. 74. 1801. 
The animal in this genus has long, subulate tentacles; eyes 
slightly prominent; foot truncated in front, rounded behind, 
grooved beneath; branchial plume very long; lingual ribbon 
minute, denticulated.. Carnivorous ? 
The species range from low water mark to 100 fathoms; their 
geographical distribution is extensive, embracing most tropical 
and temperate seas. 
1. T. ERosa, Couthouy. Fig. 130. 
Bost. Journ. Nat. Hist., ii. 108, t. 8, f. 1. 18388. 
T. polaris, Moller, Ind. Moll. Scand. 1842. 
Shell turreted, elongated; 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; strie of growth wrinkling the shell longitudinally; apex 
often eroded; aperture circular; lip thin and impressed by the 
termination of the coste; columella with a slight callus and 
angular base; reddish-brown. 
Length 12.5, diam. 3.75 mill. 
Massachusetts, northwards (Hur.). 
2. T. RETICULATA, Mighels and Adams. Fig. 131. 
Bost. Journ. Nat. Hist., iv. 50, t. 4, f. 19. 1842. 
T. lactea, Moller, Ind. Moll. Scand. 1842. 
Shell turreted, slender, grayish-white; whorls eleven or twelve, 
convex, with irregular longitudinal folds, and three to five re- 
volving striz, making the surface appear reticulated; aperture 
small, orbicular; labrum thin; operculum horny. 
Length 17, diam. 5 mill. 
Allied to 7. erosa, but easily recognized by the longitudinal 
ribs, and by its more slender form. 
o Gulf of St. Lawrence. 
