SHELL ARCHITECTURE. 
In these photographs variations in the forms of the two great classes of shells, the univalve (in the upper) and the bivalve (in 
the lower) are shown. The names of the univalve specimens are: (1) the Bonnet Shell, (2) the Coil Shell, (3) the Twisted Shell, 
(4) the Harp Shell, (5) the Egg Shell, (6) the Staircase Shell, (7) the Worm Shell. Those of the bivalves: (1) the Scallop Shell, 
(2) the Lamp Shell, (3) the Venus Shell, and (4) the Watering-pot Shell. 
