158 



CENTJS. CYCLOSTREMA. FLEMING, 

 Spire short ; transverse ridges on the body whorl, 



disjoined from the pillar by a crenulated groove. 



C. ZETLANDICA. F. p. 312. Mont. Lin. T ]\.p. 

 194. t. 13. f. 3. Conical, white, apex obtuse, whorls 

 five, tumid, ribbed spirally and longitudinally, witli 

 angular tubercles at the point of decussation, the spiral 

 ridges most prominent at the base where the longitu- 

 dinal ones disappear; aperture nearly orbicular and 

 marginated. 0,18. Zetland. 



GENUS. SKENEA. FLEMING. 

 Spire depressed and destitute of spinous processes ; 



suture deep. 



S. DEPRESSA. F. p. 313. SERPULA CORNEA. 

 Adams. Lin. T. 5. t. 1. /. 33. HELIX D. Mont. p. 

 439. t. 13./.5. Brown, whorls three or four, rounded } 

 wrinkled across, with a deep groove for the separating 

 line ; above, the whorls are nearly on a level, their cen- 

 tral edge bending suddenly at the suture and forming a 

 deep groove ; beneath, with a large central cavity ex- 

 posing the volutions ; aperture circular, detached from 

 the body whorl, sometimes slightly reflected. 0,08, 

 At the roots of Fuci, not uncommon. 



S. SERPULOIDES* F. p. 313, HELIX S. Mont. 



