MOLLUSCA OR UNIVALVES. 225 



wide ; operculum horny. Animal unknown. — 

 28 species recent, and 6 fossil. 



A common and numerous ge- 

 nus, chiefly from the Indian 

 Ocean and Red Sea. The Py- 

 rula canaliculata is found in the 

 Northern Ocean; it is a large 

 but light shell, six inches in 

 length. The Pyrula candelabrum has the spire 

 quite flat, and if placed upon that part will 

 stand upright ; it is very rare. The Pyrula 

 ficus very nearly resembles a fig in shape, 

 from whence its name is derived. Some 

 of the species have an umbilicus. In the 

 British Museum is a specimen of a Pyrula 

 bezoar that appears to have grown with per- 

 fect regularity until the formation of its last 

 half whorl, which is thrown considerably more 

 than half an inch out of its proper position by 

 a group of barnacles. These shells had pro- 

 bably attached themselves to the back of the 

 Pyrula at an earlier stage, and as the latter 

 increased in size at length filled the place that 

 should have been occupied by the inner lip, 

 which, on meeting with this interruption, di~ 



Q 



