PELECYPODS 

 GENUS Tagelus 



459 



T. gibbus. The extended range and shore station of this exceedingly 

 abundant species will cause it to be among the first accessions to the 

 cabinet of the collector south of Cape Cod. It burrows deep in sand 

 and mud, leaving two small openings to the hole for the accommodation 



Tagelus gibbus, showing extended animal. 



of its two excessively long siphons. As in Solen and Ensis, the foot is 

 large and muscular, tongue-shaped, and capable of remarkable change 

 of form and great freedom of movement. The long white siphons, sepa- 

 rated from the base and each provided with orange-colored eyes (or, 

 rather, a rudimentary sort of visual organs), are the most important 

 feature. The apex of the hinge is not, as in Solen and Ensis, at the end 

 of the shell, but is more conventionally placed near the middle ; the 

 cardinal teeth are very small, two upon each valve and interlocking ; 

 a flat, oblong, callous process serves as a fossette. The dorsal and 



ventral margins are parallel, and 

 gape at both ends ; the shell is white, 

 and is covered with a dense yellow- 

 ish epidermis, which, passing the 

 ventral margin, appears to become 

 continuous with the thickened man- 

 tie-edge There is no other species 

 north of Hatteras with which this 

 could be confounded. The double entrance to the burrow, which may 

 be discovered about low-tide mark, is unique. T. gibbus is a good spe- 

 cies to examine for the crystalline stylet in the digestive tract. 



FAMILY GLYCIMEEIDJE 



GENUS Glycimeris 



G. generosa. A large shell of the Pacific coast, occurring most 

 abundantly in Puget Sound waters, where it frequents muddy shallows. 

 It is a remarkable pelecypod in respect to its siphons and the degree of 

 mantle fusion. The appearance of the animal is that of a huge pair of 



