MYA-GAPER. 151 



others are remarkable for their thick, solid, and 

 substantial shells, and have in consequence been 

 formed into a distinct genus, called Unio. Many 

 of the mollusks of this genus burrow in the sand 

 or mud, boring a channel through which they 

 thrust a contractile trunk inclosing two tubes. 

 The Myse furnish food not only for man, but also 

 for many aquatic birds. 



MYA Truncate* 



TRUNCATED GAPER. 



Specific Character. Shell ovate, convex, trun- 

 cated at the anterior end, where it gapes con- 

 siderably ; curved at the areola, wrinkled trans- 

 versely, and covered with a brownish yellow tough 

 epidermis, extending an inch or two beyond the 

 gaping end, like a thick membrane, through 

 which the animal protrudes its tube ; hinge with 

 a rounded tooth projecting forwards ; inside 

 white ; length from one to two inches ; breadth 

 from two to three. 



These shells inhabit the sand or gravel about 

 low water mark on most of the northern coasts of 

 Europe. In Greenland, their mollusks are the 

 food of man and different animals. When taken 

 alive, the epidermis of the shell is found joined 

 to the tube or proboscis of the animal, having 



* Plate VII. fig. 3. 



