i;6 



Monoculi and the minute bivalve tcJloLcea is, that the lat- 

 ter always, more or lefs, poIFefs fome concentric wrinkles 

 or annulations of growth, as well as fon)e appearance of 

 umbo or beak : fuch therefore, which are deftituteof thefe 

 marks, may with confidence be referred to the former. 



If any fuch doubtful objecls are put into water, even 

 after the animal has been long dead and dried ; and when 

 fofiened, the valves carefully opened with the pomt of a 

 fine needle, and afterwards put into a drop of water un- 

 der a microfcope ; the ante7incs and legs will foon appear, 

 if a Monocidus. 



GEN. 



