406 MURICID^. 



nated ; an extremely elongated shell with strong ribs and 

 no epidermis, but remarkable for having a groove en- 

 circling the upper part of the body-whorl. The two last 

 are in Mr. Alder's collection. 



]\Ir. Jeffreys has a carinated form from the mouth of 

 the Thames procured by Mr. Sowerby, a pleurotomatous 

 monster taken by Mr. Barlee on the west of Scotland, 

 and a scalariform lusus taken off South Devon. 



Buccimim undatum varies considerably in colour through 

 various shades of plain white, to a general purple tint, 

 or chestnut banded on a white ground, or blotched with 

 brown, or entirely brown. It grows to the size of six 

 inches long by three wide. 



The general colour of the animal is yellowish white, 

 sometimes with a tinge of tawny, and usually mottled 

 with irregular blotchings, or specklings of black, which 

 are especially conspicuous on the sides of the foot, head, 

 tentacula, and siphon. The head is broad, rather small 

 in proportion to the body, and flanked by two lanceolate, 

 flattened, rather obtuse tentacula, with thickened and 

 widened bases, on which on hulgings, externally, are borne 

 the blue-black eyes : the tentacula are distinctly separated 

 from each other by a frontal slightly bilobed space. The 

 siphon is long, and recurved when exserted. The male 

 organ is massive, very large, elongato-pyriform, with a 

 short lanceolate mucro on its upper extremity ; the foot 

 is vast, when creeping much expanded, obscurely trun- 

 cated in front, rounded behind, and bearing the opercu- 

 lum on a rounded lobe without process. The operculum 

 is strong, corneous, brownish yellow, and composed of 

 subconcentric elements round a sublateral nucleus. The 

 proboscis is long and ample ; the axile tongue-teeth are 

 broad and serrated, with many denticles below ; the 



