CONUS. ORTHOCERA. 141 



ly, longitudinally, or in bands. At times the shell 

 is white, and the spots clouded with orange or 

 violet blue; towards the base it is slightly grooved; 

 and the spire is acuminated, with its lower whorls 

 slightly concave. 3|. W. 16. 136. 



CEPHALOPODES. 



ORTHOCERA, 



Elongated, straight, or slightly curved, sub-coni- 

 cal, striated externally by numerous longitu- 

 dinal ribs; chambers formed by transverse 

 septa, perforated by a central or marginal 

 tube. 



O. cosTATUS. Sub-cylindric, straight, with 

 four strong longitudinal ridges, but little taper- 

 ing ; sub-globose ; twelve chambers. \. B. W. 

 13. 25. 



O. JUGOSUS. Sub-cylindrical, slightly curved, 

 with numerous longitudinal ribs, and nine globose 

 chambers, the first the longest, the last produced 

 into a conical neck, with a round aperture ; brown. 

 h. B. W. 13. 22. 



