488 MURICID^. 



in forming the canal ; it oftentimes projects almost at 

 right angles to the body. The upper half of the inner lip 

 is moderately incurved, the lower half bends rather sud- 

 denly in a straightish or scarcely curved line to the left. 

 The largest specimen we have seen measured three quar- 

 ters of an inch in length, and a third of an inch across ; 

 in general, however, examples are only five-eighths of an 

 inch long and about half as broad.* 



The animal is entirely wdiite or yellowish white. Its 

 tentacula are rather short in proportion to its size. Its 

 foot is truncated and ungulated in front, triangular and 

 obtuse behind. The axile denticles of the tongue have 

 obtuse angles, and two rather small, closely set denticuli 

 on each side of a larger central one. 



This species is very rare, or absent, on our southern 

 shores, but abundant from the southern entrance of the 

 Irish sea northwards to Zetland. It is frequent also on 

 our eastern coasts, and is found all round Ireland. It 

 ranges from five to fifty fathoms. It is distributed 

 throushout the boreal and arctic romons of the North 



o o 



Atlantic. 



* A fragment (the first four whorls) of a much larger shell (that must have 

 vied in dimensions with the larger figure of Bamffius in Donovan) has been taken 

 in the North by Professor Macgillivray. From the size of its volutions, and the 

 remoteness of its lamellise, it appears to belong to the scalurifonnis of Gould 

 (Invert. Massach. p. 288, f. 203; Murex lumellatus, Philippi, Neue Conch, 

 vol. iii. p. 41, Mur. pi. 2, f. 2), which Loven and MiddendorfF consider to be 

 merely a large boreal variety of dalhratus, from which, indeed, it differs in little 

 else than size, its more capacious mouth, more arcuated lip, slightly longer spire, 

 and rather straighter, longer, and abruptly slender beak ; the first of which fea- 

 tures, though all are present in the more characteristic examples, alone seems 

 pennanent. It is so connnon and characteristic a shell in British pleistocene 

 water, that the fragment in question may liave been part of a fossil. 



