78 THE AMERICAN MONTHLY [Mar., 



have sometimes noticed living specimens of large size and 

 peculiar structure, whose make-up caused me to suspect 

 that certain forms illustrated in the books and classed in 

 different genera were merely different parts of the same 

 organism, but circumstances prevented the thorough in- 

 vestigation necessary to demonstrate the facts, and I 

 therefore mention it merely as a suspicion. At the eas- 

 tern end of Leete's Bay is " Shell Beach " extending from 

 tlie main land to Leete's Island, and crossing the ancient 

 channel which once surrounded the Island ; this beach 

 has a local celebrity on account of the number and va- 

 riety of the shells cast up by the tide ; among these are 

 many species of small round clams, one of these averages 

 about the si/e of a common cherry stone. A larger spe- 

 cies has a bright pink color and very thin shell. The 

 razor shell or Solen, K. ettsis is numerous in all sizes, and 

 Fnlgar odriea and F. {•futalicfthttfist are plentiful, Mnrt-f, 

 Neli.i; Hdiciva, Zonites, N<(.sft(i and other genera with 

 P^eurototna minima and Littorina ohtiisata abound. Af- 

 ter the storm, living specimens which had the form and 

 outline of Leda sowerhyana, but which did not gap at 

 extremities and had the polished surface of Leda corpnl- 

 onta w'ere left upon the beach. The row of minute sharp 

 pointed teeth possessed by these shells is a peculiar fea- 

 ture of their structure. Near the point of the island and 

 on the north shm-e of (Ireat Harbor, I picked up two or 

 three dozen of the rare shells of Paitdora ceyloitica. 



Shell Beach is being slowly driven inland by the sea : 

 its recession is laying bare deposits laid down many 

 years ago, the diatoms of these deposits are much like 

 those of the soundings. I find them difficult to clean on 

 account of the quantity of minute scales of mica they 

 contain, which are almost impossible to separate by or- 

 dinary methods. I have made a few slides by separat- 

 ing the heavier discoid forms by the process first pointed 

 out by Christopher Johnston, M. D., in Tlie Leu.s of No- 



