250 Mr. W. King on some Shells and other Invertebrate Forms. 



displayed on the inside of the aperture ; occasionally there is so 

 little calcareous matter in the shell that it is almost horny. 



Variety Buccinum litt oralis is so called in consequence of only 

 being found close in shore on pebbly bottoms and rocks laid bare 

 at low tide. From being on such rough and exposed grounds, 

 it is extremely liable to become broken and abraded, which will 

 account for so few being found in a perfect state : at one locality 

 near Sunderland, it is however often found in beautiful condi- 

 tion ; here the specimens are always white externally with a yel- 

 low aperture : in various other localities on the coast of North- 

 umberland, it is brown externally, and of a variously shaded 

 purple colour within. This variety, at least as it occurs near 

 Sunderland, has the waves rounded, regular, and not very promi- 

 nent : the cords and threads are closer to each other than in 

 B. magnum, from which it differs in being a shorter and a smaller 

 shell, in having a shorter spire, the whorls standing less boldly 

 out from the sutures, and the terminal margin of the canal less 

 reflected. The epidermis is thinnish and of a light brown colour. 

 My largest specimen measures 2 \ inches in length and 1 \ in 

 breadth, and has eight whorls ; it is very seldom that specimens 

 are found exceeding this size. 



Besides the foregoing, another strongly marked variety occurs 

 on our coasts ; but as it is probable it will be described elsewhere 

 by others who have paid more attention to it than I have, I shall 

 merely state, that one of the principal differences between it and 

 Buccinum magnum, as first pointed out to me by Mr. A. Han- 

 cock, is in the general absence of an epidermis ; the fishermen 

 say that it lives on hard or rocky ground. The figure in Pen- 

 nant's l British Zoology/ pi. 73, appears to represent the same 

 shell. I have seen two aberrant forms of this variety ; one is 

 thin, waveless and subulate, somewhat resembling the Buccinum 

 acuminatum of Broderip ; and the other is of the normal form, 

 but without any waves. 



To the conchologist who is interested in the modifications to 

 which a species is subject from a variation of habitat, depth, or 

 from other causes, nothing can be more pleasing than to see the 

 various permanent forms of Buccinum undatum belonging to our 

 coasts ; but how much more interesting would a collection be of 

 all the varieties that are known to live under every shade of cli- 

 matal influence ! Deshayes says that Buccinum undatum is found 

 ranging " from the North Cape to Senegal, modifying itself ac- 

 cording to the temperature as it advances* :" it is well known to 

 occur on the shores of North America ; and the paleontologist is 

 certain that it lived as far back as the meiocene period. I have 



* Charlesworth's Magazine of Natural History, vol. i. p. 10. 



