188 



U, » Ono other species hag made its appearance in the 



City Mill Pond about ten years since ; there had not been 

 any before for thirty years. I also found it in Forest River, 

 1836. It inhabits a little below low water mark, and lives 

 two years only. 



Anatifa. 



A. Isevis. Found on vessels bottoms. I have known it to 

 grow I of an inch, from April 1st to Oct. 20th. 



A. striata. On bottoms of vessels. 



A. dentata. On bottoms of vessels ; when alivo the pedun- 

 cule has a granulated appearance — whereas the pedunculo of 

 IcBvis and striata is smooth, 



A. sulcata. Found on sea- weed on all the beaches. I have 

 never found it on vessels' bottoms. 



Cineras. 

 C. vittata. A few specimens found near City Mills, and on 

 vessels' bottoms. 



Teredo. 

 T. navalis. Have found three distinct varieties of Teredo ; 

 one from Phillips' Beach had a globular shell, the valves closed 

 in front, a small square aperture where it joined the neck of 

 the animal ; made a serpentine flattish burrow, and not lined 

 with shell. 



Pholas. 



P. dactylus. A single specimen, found in decayed wood at 

 Phillips Beach. 



P. sp. Found in pieces of wood from the bottom of City Mill 

 Pond. Its shell is furnished with a large dorsal piece at the 

 summit ; a line on the outside from summit to base ; and near 

 the base a corresponding rib ; at the end of which is a ligament, 

 which confines the valves together at the base. This Pholas 

 is like species imported in mahogany logs from West Indies ; 

 its burrow is not deep, and about twice the length of the shell. 



P. crispata. Found living at King's Beach in Lynn, nearly 

 opposite the mouth of Stacy's Brook, in hard clay. The speci- 

 mens were small, the shells from 2-8 to 7-8 of an inch long ; 

 shell widely gaping at both ends ; a furrow from the summit to 

 the middle of the base, with a corresponding rib inside, a liga- 

 ment at the end of the rib, which confines the valves together 

 at the base ; a tough membraneous epidermis nearly covers the 

 posterior or upper end, forming at the edges of the shell a case 

 for the tubes ; tubes connected by a membrane, a small acces- 



