Ha!
Well, by crackers, it is in fact the the plain old Quahog clam. And Horge,though measurements are imprecise, some of those show 250+, which gives a little room for error
. Scientist around here(couple of blocks) feel that measurement is probably +/- about 15%-and feel pretty comfortable about that.
Humans are the longest-lived mammals and giant tortoises are the
longest-lived reptiles, sometimes living as long as 150 years. Among
birds, the record is held by turkey buzzards at 118 years. But
thick-shelled ocean clams called quahogs hold the top longevity
record among all animals. These slow-moving mollusks can live more
than 200 years.
Quahogs are burrowing clams that feed on microscopic life they strain
from the water. They use their fleshy foot to pull themselves under
the mud, then extend two long tubes up into the water.
Native to the North Atlantic Ocean, quahogs are in great demand as
food for people, and as a result, those found near shore seldom live
longer than 10 or 20 years. Like many other North Atlantic life
forms, populations of quahogs have been reduced greatly in some areas
due to overcollecting.
Quahogs can be made into very good clam chowder:
http://www.assateague.com/clam.html
http://www.parker-river.org/nat_hist/shellfsh/quahog.htm
http://seagrant.gso.uri.edu/G_Bay/quahog.html
And sorry for so long replying again--but I was still having no luck connecting.
b.