112 % STROM BUS. 



one of which is prolonged in a curved manner to the extent of 

 an inch and a half. The specimen has rather the appearance of 

 being malformed ; but notwithstanding this seeming irregularity 

 of growth, there is no doubt whatever of its being specifically 

 distinct from any hitherto described form." 



Section III. MONODACTYLUS, Klein. 

 S. PERUVIANUS, Swainson. PI. 3, fig. 29. 



Whorls spirally ribbed, obtusely angled and tuberculated on 

 the shoulder, middle tubercle on the back very prominent ; 

 yellowish chestnut, sometimes a little tessellated, aperture and 

 columella yellowish or orange-brown, deepening in the interior 

 to a deep orange-red. Length, 5-7 inches. 



Peru to W. Columbia. 



In old specimens the interior of the outer lip is often radiately 

 ridged. 



S. TRICORNIS, Lam. PI. 3, figs. 30, 31. 



Nearly smooth, very obsoletely spirally ribbed, the shoulder and 

 spire tuberculated, dorsal tubercle of body-whorl long, laterally 

 compressed, very prominent, two other dorsal tubercles also 

 somewhat enlarged ; whitish closely irregularly lineated with 

 orange-chestnut ; aperture blush-white or rosy. 



Length, 4-5 inches. 



Red Sea, Isle of Bourbon, Seychelles, Philippines. 



Is a smaller, lighter species than the preceding, with the lip 

 more narrowly produced into a lobe behind, interior always 

 smooth, spire longer, aperture light violaceous instead of orange- 

 red. It is not West Indian, as supposed by Sowerby. It is S. 

 orientalis, Johnston, and S. pertinax, Duclos. 



S. BITUBERCULATUS, Lam. PI. 4, figs. 32, 33. 



Grayish white, marbled and banded with chestnut or chocolate, 

 aperture yellowish white, deepening to rose-color. 



Length, 3 inches. 



West' Indies; N. South America. 



It is S. lobatus, Swainson, S. quadratus, Perry, S. raninus, 

 Gmelin. The latter name has priority, of course, but I prefer 

 to retain the name under which the species has become so well- 

 known. 





