CHAPTER XXV. 



The Washington Clam— The Introduction of the Mya 

 — Platyodon — The Great Northerner— The Pid- 

 DOCKS- Zirph.ea- Parapholas — The Teredo — Brach- 



lOPODS — LiNGULA — CEPHALOPODS — OCTOPUS — ThE 



Squids. 



THE great Washington clam is a huge, burrowing 

 mollusk, living sometimes fully two feet below 

 the surface of the mud. For such a situation it is 

 provided with an enormous siphonal tube, through 

 which it holds communication with the upper world. 

 Living so deep in the mud, they are rather hard to 

 capture, but when they have been traced and spaded 

 out a very few of them are sufficient to make an ample 

 and excellent chowder. 



The shell of this SchizothcErus Nuttalli^ Conr., Shi- 

 zo-the'-rus Nut-talF-i, for that is its name, is oblong, 

 bulged, rather thin, and it gapes widely at the end 

 where the siphons pass. The hinge-teeth are small, 

 and the large internal ligament is lodged in a trian- 

 gular pit. As you might suppose, the pallial sinus is 

 very broad and deep to make room for the huge 

 siphons. The white shell is sometimes covered with 

 a thin epidermis. This great mollusk delights in 

 muddy bays, where its shell sometimes grows to a 

 length of ten inches. It is found along our whole 

 western coast, from the Sound to Mexico. 



Cryptomya Cah/or7iica^ Conr. ^Cryip-to'-vai-Si. Shell 

 elliptical, slightly gaping, nearly smooth, sometimes 



