POST-GLACIAL HISTORY OF BOSTON. 453 



Macoma halthica* — The Exeter Street shells are very abundant; 

 they are normal in size and shape, an average sized specimen measuring 

 25 mm. long by 20 mm. high. Those specimens preserving the epider- 

 mis are usually bluish-black in color. 



The Muddy River forms are very similar to the Exeter Street 

 specimens, as are also the ones from beneath the Copley Plaza Hotel, 

 and from Berk.ele\' Street. 



The average of ten specimens from Exeter Street gave 1 to 1.20 

 as the proportion of height to length, as against a proportion of 1 to 

 1.23 in specimens from Eastham, Massachusetts, the recent shell 

 thus showing a similar lengthening to that noted in Gemma gemma. 



Ensis directum. — The razor-clam, though now but little used as food, 

 was highly esteemed by the early settlers. It is much more abundant 

 at the Berkeley Street than at the Exeter Street locality. 



Mulinia lateralis. — In the specimens from Exeter Street the average 

 proportion of height to length was 1 to 1.17, while the larger recent 

 shells from Woods Hole are in the proportion of 1 to 1.22. 



Mya arenaria. — The common sand clam, soft clam or long-neck 

 clam. Among specimens of this very abundant species at Exeter 

 Street are some large ones with a length of 100 mm. and height of 55 

 mm . The Muddy River forms are normal in shape and size. The 

 Charles River specimens seen average 110 mm. long by 65 mm. high; 

 there are some 128 mm. by 80 mm. Those seen from the Copley 

 Plaza and the numerous forms from Berkeley Street are similar to 

 those from Exeter Street. The City Point forms are in size and 

 abundance similar to those from Charles River. 



That the long-neck clam was very abundant here during the early 

 colonial days is shown by the following quotation (6) : — 



"Clames is a shell fish, which I have scene sold in Westminster 

 for 12 pe. the skore. These our swine feeds upon, and of them there 

 is no want; every shore is full ; it makes the swine proove exceedingly, 

 they will not faile at low water to be with them. The Salvages are 

 much taken with the delight of this fishe, and are not cloyed, not-with- 

 standing the plenty: for our swine we find it a good commodity." 



Odostomia trifida. — A single, small (3 mm. long), well preserved 

 specimen was noted at Exeter Street. 



Odostomia bisuturalis. — The specimens from Exeter Street are 

 small, averaging 3+ mm. in length and with a proportion of width 

 to length of 1 to 2. 



* DaU, after a careful comparison, considers the American specimens referable 

 to the European species M. balthica. 



