IN DESCRIBING SHELLS. 37 



Subulata is when it is long and slender, as in Murex Haustdlum, 



Tnbidiis, and cor nut us. 

 Recta is when it stands in a straight line, as in Murex baby- 



lonius. 

 Flexuosa is when it is bent on one side, as in Murex L.otorium 



and Pyrtini. 

 Recurva or Rejlexa is when the tail is bent back, as in Ruc- 



cinum cornutum, rufum, and tuberosum. 

 Adscendens is when the tail rises upwards supposing the shell 



to be laid with the mouth downwards, as in Murex Pileare, 



reticularis, and Vertagus. 

 Erecta is when the tail is turned quite upright supposing 



the shell laid with the mouth downwards, as in Murex 



Anus. 



OF THE LIPS, LABIA. 



Explanatum is when the left lip is spread out on the last 



whorl, as in Ruccinum gibbosulum and neriteum. 

 Striatum is when there are lines marked on the inside of the 



outer lip, as in Ruccinum hcemastoma and undosum. 

 Edentula is when the lips are without teeth on the edge, as in 



Nerita fluviatilis and lacustris. 

 Dentatum is when there are sharp points or projections on the 



edge of the outer lip, as in Strombua Fusus. 

 Muricatum is when there are sharp points on the edge of the 



lip, but not so large as Dentatum, as in Ruccinum Vibex and 



Erinaceus. 



