PYRULA. 



into ^commerce; and their outer lip which, when perfect 

 is thickened a little on the outside, is for the most part 

 so brittle, that it seldom remains when the shells them- 

 selves adorn our cabinets. They are pyriform, ventricose 

 above, rather attenuated below, - and generally very 

 regular: the spire is very short and rounded 5 the aper- 

 ture is elongated, produced into a short, broad canal, 

 narrower at its superior extremity, and broader in the 

 middle on account of the columellar sinus. There are 

 no varices; the outer lip is sharp edged, and very mi- 

 nutely crenulated. Inner lip very thin, expanded, some- 

 times scarcely visible. Umbilicus none. We suppose 

 the animals of this Genus to be furnished with an horny 

 operculum, but we have never seen them. 



The only shells we admit into this Genus, are such 

 as are commonly called Figs in commerce, they are dis- 

 tinguished from all others, by the regularity of their 

 form, and the thinness of their shells; they are mostly of 

 a whitish colour, and speckled with brown; sometimes 

 violet within and seldom entirely white on the outside. 



Several species are common in a recent state, they 

 are principally brought from the East Indies. In the 

 fossil state they are frequent in the Calcaire grossier, near 

 Paris; they are also found at Bordeaux; and we have 

 them in the London clay, at Bognox*, Hordwell, &c. 



Fig. 1. Pyrula reticulata, Lam. 



2. Burdig-alensis, Defr. a fossil species from Bordeaux. 



3. tricarinataj Lam. another fossil species from aear Paris. 



