GASTROPODA— CONIDJE. 



805 



ribs extending beyond the lower suture ; spirals fine, numerous. 

 Chesapeakean of Maryland, etc. 



Family Conid^e Adams. 

 CXCVI. Conus Linn. 

 Whorls with a narrow shoulder and straight sides, the angle 

 between the two being more or less pronounced; the whorls em- 

 brace to the shoulder angle thus making a continuously sloping 

 spire, which is generally steepest in the young, and may be at right 

 angles to the axis; forward, the tapering of the shell is a regular 

 one, producing the conical form; aperture long, narrow, with an- 

 terior and posterior canaliculation ; outer lip sharp. Cretacic- 

 Recent. 

 637. C. planiceps. (Fig. 11 82.) Oligocenic. 



Fig. 1 182. Conus planiceps, summit and apertural Fig. 1183. Conus diluvi anus, 

 views, young shell, X 2 -3- (After Dall.) X Vz- (After Dall.) 



Spire low, conical, with papillose apex ; shoulder surfaces gently 

 concave with a strong revolving spiral near the suture. 



Vicksburgian of Florida; Chipolan beds of Gulf States. 

 638. C. diluvianus Green. (Fig. 1183.) Miocenic. 



Spire steep, slightly terraced in the young from failure of the 

 whorls to embrace freely to the angle; surface faintly grooved just 

 below the suture, and concave above the angle; base of columella 

 slightly twisted inwards. 



Chesapeakean of Atlantic coast. 



