SOME OF THE BIVALVES OF NEWPORT. 
By S. JACOB.* 
I had hoped to place before the Society one or two new varie¬ 
ties that I had found on my previous visits to the beach, but hav¬ 
ing forwarded the specimens to Europe I have been unable to find 
duplicates, and my subject being a very long one I am reluctantly 
compelled to confine myself to the following well-known varieties. 
I say reluctantly from the fact that the varieties exhibited have 
been known to students of conchology so many years that I am 
afraid not very much that is new can be said in regard to them. 
But thinking established facts might be of interest to the Society 
I have prepared this paper. 
Acephalous mollusks with bivalve shells is the name given by 
modern naturalists to the order of animals of which I have now 
to speak. The word acephalous comes from the Greek and 
means headless. I have specimens here of Ostrea cdulis or edi- 
I ble oyster, Mytilus edulis or edible mussel, Pecten -pleuronectcs 
or flounder scallop, Pccten latiauratus or dancing scallop, Solen 
crisis or razor shell, Venus mcrccnaria or quahaug, My a mcr- 
ccnaria (M. arenaria ) or soft clam, Mactra gigantca or deep 
sea or beach clam and a fresh water Unio from Easton’s Pond. 
The American oyster, having gained such a world wide repu¬ 
tation, has led me to devote most of my paper to that animal and 
to occupy most of your time with details as regards him. It is 
described by conchologists as follows:—Animal; body com¬ 
pressed, more or less orbicular, edges of the mantle thick not ad¬ 
hering or retractile, and provided with a double row of short and 
numerous tentacular filaments; two pairs of elongated and trian¬ 
gular labial appendages; a subcentral bipartite muscle. Shell ; 
irregular, inequivalve, inequilateral, roughly foliaceous, the left 
or inferior valve adhering, larger and deeper than the other, its 
summit prolonged with age into a sort of heel; the right or supe¬ 
rior valve more or less operculiform ; hinge oval, toothless, 1 iga- 
♦Read before the Society April 8th, 1SS5. 
