PLATE LXXXVIIT. 



Da. Costa observes, that all the shells he had seen of this species 

 were fished up at, or near, Weymouth in Dorsetshire; and concludes, 

 that it is rare in our seas, having never heard of it on any other Bri- 

 tish coast. We believe with Da Costa, it is local; though it prcf- 

 bably inhabits other parts of our coasts. 



We have been lately favoured with several shells of the Bulla 

 genus from Portsmouth, which some Conchologists have thought a 

 new species, and named Citrina ; they do not, certainly, differ spe- 

 cifically from the shell in Du Costa's collection, which he calls 

 Bulla Naviacula, (Hydatis of Linnseus) as will appear evident from 

 the specimens figured in the annexed plate. 



Fig. 1. — Bulla Naviacula (Hydatis Linn.) Fig. 2, a specimen 



from Portsmouth of a paler colour than Da Costa's shell.— ——Fig. J t 

 4. old shells found on the mud and clay of the shore. 



