70 



Shell Life 



Tulip Horse 

 Mussel 



the last, thin and glossy, of a yellowish hue, the 

 hinder portion being also usually marked with rosy 

 or purple streaks after the manner of 

 a tulip. The thin polished epidermis 

 is almost transparent. It occurs very 

 locally in Scotland, more frequently in 

 the south of England, around Ireland, 

 and along the Welsh coast, preferring a 

 bottom of gravel or sandy mud, at depths ranging 

 from 7 to 40 fathoms ; but it cannot be reckoned as 

 at all a common shell in British waters. The 

 general aspect of the Bean Horse Mussel (i/. j)liase- 

 oliniis) is similar to that of the Bearded Horse 

 Mussel, owing to the manner in which the epidermis 

 is split up into slender processes. But the difference 

 may be seen at once if one of these filaments be 

 examined, for neither of its edges is bearded as in M. 

 harbatibs. Stripped of this shaggy coating the 

 shell would be seen to be very much the shape of a 

 kidney-bean, as indicated by the name jp^iaseolinns, 

 and of a yellow colour tinged with purple. The 

 hinge-plate is sculptured into a series 

 of round teeth. It is about three- 

 fourths of an inch in length. It is 

 common on all our rocky coasts from 

 low water to a depth of 86 fathoms. 

 It often disguises itself by spinning up fragments of 

 shell and gravel with byssus into an outer envelope. 



The "crenulated" or notched hinge and upper 

 margin of the last species constitutes a connecting 

 link with the genus Crenella, which has obtained its 

 name from such ornamentation. The shell resembles 

 that of Nucida in the fact that it is entirely 



Bean Horse Mussel 



