On the Mollusca of Long Island. 163 



numbers of Bissoa mititda, and compound Ascidians in a large 

 salt-water pond, communicating with the bay only during 

 storms. 



75. Cytherea convexa Say. One dead valve was dredged in 

 Gardiner's Bay. On the south side of Montauk Pt., dead 

 valves are not uncommon. 



76. Petricola dactylus Say. Kather rare. 



77. Petricola pholadiformis Lamarck. Much rarer than the 

 preceding. 



78. Mactra lateralis Say. Eare. Two faths. mud. Five or 

 six faths. sand. 



79. Mactra solidissima Chemnitz. Alive, rarely, in sand at 

 ten faths. but not more than two inches long. Dead valves are 

 not uncommon in deep water, but I have never found them 

 more than three inches long; whilst around Montauk Pt. I 

 have obtained it seven inches long. 



80. Kellia plamdata Stimjpson. Rare. A few specimens 

 were found alive at low water mark in mud, and a few dredged 

 in four to six faths. mud, 



81. Montacuta elevata Stimjpson. Only one valve found. 



82. Tellina tenera Say. Moderately abundant. Two to 

 eight fathoms generally in sand, though sometimes in mud. 

 When placed on the surface of sand in a basin of salt-water, it 

 goon extends its foot, and by a single eifort jerks itself upright, 

 and then, with two or sometimes three strokes, completely 

 buries itself, 



83. Tellina tenta Say. Less abundant than the preceding 

 species. In sand at six faths,, and mud at two faths. 



84. Tellina fusca Phil. Abundant dead, and rare alive in 

 mud near low water mark in a large shallow salt water pond, 

 communicating freely with the Bay. The specimens were 

 white, yellow, pink and bluish in about equal proportions, were 

 very thin, and averaged three quarters of an inch in diameter. 

 Also dredged, rarely, in sand at six faths., very small and light 

 pink. 



