66 



be umbilicated, and the aperture is nearly oval, terminating in an open 

 canal. 



The original shell, with the twirls passing from the left to the right, 

 of which the one just spoken of may be considered as a variety, has not 

 been yet mentioned as having been found in the Essex clifK Dale, in- 

 deed, queries whether Buccinum roslratum, out of Harwich cliff, thus 

 mentioned by Woodward, Catalogue, Part n. /?. 37, e. 115, may not be 

 referable to this shell : but this can hardly be supposed, from so general 

 a designation ; since, having so strongly particularized the reverse shell, 

 it is not likely that he would have omitted to point out this as being the 

 same shell, turning in the ordinary direction. 



In the many visits which my late respected friend, Dr. Menish, paid 

 to this cliff, he discovered two specimens of this shell, with the whirls in 

 the ordinary direction. My repeated researches having been always 

 unsuccessful, I purchased these shells from Dr. Menish's collection. 



One of these seems to differ from the heterostrophe in not having its 

 whirls so obliquely disposed, in the spire not being so long, in the 

 aperture being every way larger, and in the left lip rising higher, and 

 being larger and more detached. The other is a very old shell, and 

 measures full five inches in length, and three in width. 



A shell, which has been supposed to resemble this last-mentioned fos- 

 sil, has been found on the coast of New Holland ; but the columella, in 

 this shell, is so nearly naked, as, I think, renders it specifically different. 

 A recent shell is however found on the Essex coast, turning the right 

 way, which very nearly, if not exactly, agrees, in its specific characters, 

 with the heterostrophe. 



Lamarck describes seventeen species of this genus as found fossil in 

 the neighbourhood of Paris : M. tripterus, M. tricar inatus, M. contabulatus, 

 M. calcitrapa, M. crispus, M. frondosus, M. clathratus, M. cingulatus, 

 M. striatulus, M. cancellinus, M. pyraster, M. textiliosus, M. colubrinus, 

 M. Viperi?ws, M. nodularius, M. reticulosus, and M. tubifer. 



