STROMBIDJE. 101 



Section III. MONODACTYLUS, Klein, 1753. Lip with a pos- 

 terior, narrow, much produced lobe. S. Pacificus, Swainson. 



Section IV. GALLINULA, Klein, 1753. Lip somewhat dilated, 

 not digitate, frequently- descending the spire behind ; inner lip 

 restricted, defined. S. succinctus, Linn. 



Section V. CANARIUM, Schum., 1817. -Lip not dilated, pos- 

 terior canal short or obsolete. S. urceus, Linn. 



Section VI. CONOMUREX, Bayle, 1884. .Shell cone-shaped, 

 with short spire, aperture narrow, with subparallel lips, the 

 outer lip not dilated. S. Luhuanns, Linn. 



Section VII. ONCOMA. Mayer, 187(5. Fossil, Eocene of Europe. 

 S. and S. Conch., ii, 190. 



Subgenus PUGNELLUS, Conrac^ 1860. 



Fossil only, Cretaceous U. S. S. and S. Conchology, ii, 190, t. 

 60, f. 71, 72. 



Section GYMNARUS, Gabb, 1868. Fossil. S. and S. Conch., ii, 

 190, t. 60, f. 73. 



Subgenus PEREIR^EA, Crosse, 1867. 



Fossil only. Miocene of Spain and Portugal. S. and S. 

 Conch., ii. 1&4, t. 60, f. 87. 



Genus PTEROCERA, Lamarck, 1799. 



Outer edge of the mantle digitated. Operculum as in Strom- 

 bus. Shell ovate, spire turriculated, aperture narrow, elongated, 

 outer lip much expanded, tubularl}- digitate, with a sinus near the 

 base, a long, straight or curved anterior canal, and a posterior 

 canal ascending and sometimes surpassing the spire. 



The young shell, like Strombus, is coniform, with the outer lip 

 straight and simple; the claws or digitations being gradually 

 formed with the growth of the shell. At first they are short, 

 open canals, and afterwards close and become solid. 



Section I. PTEROCERA (sensu stric.to}. Anterior canal straight 

 or curved to the right, posterior canal ascending the spire. 



Subsection I. (Heptadactylus, Klein). Lips smooth, digi- 

 tations not numerous. P. lambis, Linn. 



Subsection II. (MiHipes, Klein). Lips rugose or corru- 

 gated, digitations more numerous. P. scorpio, Linn. 



