Fam. 56.] NATURAL HISTORY SOCIETY. 137 



1. Eupleura caudata, Say. (Fig. 37). Shell solid, with angu- 

 lated whorls traversed by 11 stout ribs crossed by numerous re- 

 volving lines ; lip thick, bordered within by raised granules ; 

 canal long, straight, narrow. Reddish-brown, white, or bluish 

 within ; operculum chestnut. Animal nearly white ; foot yellow. 

 L. 25; D. 15; An. 60°; Wh. 5; Ap. f ; canal i Ap.— Mass. and 

 south. 



3. Purpura, Brug. 



Shell oblong-oval, last whorl large ; spire short ; aperture large, 

 with a very short, oblique canal or notch ; columella flattened. 



1. Purpura lapillus, L. (Fig. 34). Shell thick and solid, 

 ovate ; spire short, acute ; whorls covered with deep, revolving 

 furrows and ridges, usually crossed by raised, scale-like wrinkles 

 of growth ; lip nrched, and subacute, with obscure, revolving 

 ridges within the margin. Color varies from white and yellow 

 to dark-red, often banded. Animal white. L. 25-30 ; D. 14-17 ; 

 An. 60°-90°; Wh. 5-G ; Ap. f-|.— Whole coast. Local south 

 of Cape Cod ; abundant north. 



Family 56. SCALARID/E. 



A small family of mainly the one genus : — 

 1. ScALA, Humph. 



Shell usually pure white and lustrous, turreted, many whorled; 

 whorls round, ornamented with numerous raised, longitudinal 

 ribs ; aperture round ; peristome continuous ; oj)erculum horny, 

 few-whorled. 



Animal with a retractile, proboscis-like mouth ; tentacles close 

 together, long and pointed, with the eyes at their outer bases. 

 Animal exudes a purple fluid when molested. 



* Species of large size over 15 long, with 8-15 ribs 1-3. 



* Species under 15 long, with 15-20 ribs.. 4, 5. 



1. Scala Sayana, Dall. Shell long conic; whorls in contact 

 and crossed by 9 well marked ribs which are continuous to the 

 apex ; spaces between polished, smooth ; anterior margin of lip 

 rounded. White with a smooth translucent, pale-brown nucleus 

 of about 3 whorls. L. 16 ; D. 6 ; An. 25°; Wh. 9; Ap. -|.-Va. 

 and south. 



2. :Scala angulata, Say. Shell conic, turreted ; whorls touching 

 each other only by the ribs; ribs 9 to each, whorl, prominent. 



