170 BUCCINUM. 



Synoptic Table of the Species of Buccimim. 

 According to Dr. Wm. Stiiu])son. 



A. Body -whorl angulated or carinated. 



a. Primary transverse ridges Hat ; secondary ridges inconspicuous. 



1. Shell thin ; aperture not patulous ; oviter lip not sinuated. 



* Whorls shouldered; aperture broadest above. B.polare. 



* * Whorls scarcely shouldered ; aperture broadest below. 



B. Grcenlandicum. 



2. Shell thick and strong ; aperture patulous ; outer lip sinuated. 



* Shell elongated. B. Donovani, 



* * Shell ovate. B. glaciale. 



b. Primary transverse ridges convex ; secondary grooves very dis- 



tinct. B. angulosum. 



B. Body-whorl not angulated. 



a. Aperture narrow. 



1. Primary ridges flat. B. striatum. 



2. Primary ridges convex ; a strong tooth-like plait on the 



columella. B. ciliatum. 



h. Aperture broad. 



1 . Longitudinal folds numerous, often interrupted or interposed. 



* Primary ridges flat. B. plectrum. 



* * Primary ridges obsolete ; secondaries conspicuous, 



crowded. H. tenue. 



2. Longitudinal folds not interru])ted or interposed. 



* Shell thick and coarsely striated. 



f Sinus of outer lip near the suture, columella short. 



B. UNDULATUM. 



f f Sinus of outer lip near the middle, columella pro- 

 jecting. B. UNDATUM. 



* * Shell finely striated, usually thin. 



t Secondary ridges easily distinguished from the 

 primaries, which are often obsolete. 

 II (,'olumella distinctly folded. B. simplex. 



II II Columella smooth, not distinctly folded. 



B. CYANEUM. 



f f Secondary ridges confoiuided for the most part 

 with the primaries 



II Longitudinal folds conspicuous. B. Totteni. 

 II II Longitudinal folds obsolete. 



B. IIUMPHRETSIANUM. 



Since the preparation of my manuscript on Buccinum, Dr. J. 

 Gwyn Jeffreys has piil»lishe(l a paper upon their synonymy, 

 whieii, in view of his discriminative ability and experience witli 



1 



