134 CONTRIBUTIONS 



cles ; substance of the shell thin ; spire elevated, pointed at 

 the apex; whorls nine; mouth two fifths the length of the 

 shell. 

 Length .6, Breadth .2, of an inch. 



Observations. This species differs from the last described, 

 in having a double row of tubercles, and in the mouth 

 being rather longer. It has a very close resemblance to 

 the P. semicolon (Sowerby).* 



P. Baumontii.-\ Plate 4. Fig. 127. 



Description. Shell ovately fusiform, transversely striate, 

 furnished with a single row of compressed tubercles near 

 the middle of the whorl; substance of the shell rather thin ; 

 apex pointed ; whorls eight, subcanaliculate above ; mouth 

 nearly one half the length of the shell. 

 Length .6, Breadth .2, of an inch. 



Observations. A beautiful little species, differing some- 

 what in its form from those above described, as well as in 

 the tubercles and striae. The tubercles are compressed, and 

 adorn the wider portion of the whorl. The striae are wide 

 apart, and below the line of tubercles these are, for four 

 or five rows, alternately, smaller. In the canal above the 

 tubercles, flexuous folds of the form of the sinus are visibly 

 and closely set. 



* Min. Conch, plate 146, fig. 6. 



t Named after the distinguished geologist Elie de Baumont. 



