CONCHCLOGY. 
conic, truncate at each extremity, with six valves 
having separate spaces between them and firmly 
adhering together; the hd consisting of four 
obtuse valves. 
Includes the Lepas diadema. 
8. Balanus. Shell fixed, conic or elongated, with 
six unequal valves and spaces closely united ; the 
lid two-parted, consisting of four pointed valves, 
the hinder pair a little prominent. 
Containing the Lepas balanus, Balanoides, 
Conoides, Rugosus, Scoticus, and Punctatus. 
6. Clisia, Shell fixed, compressed—conic, closed 
at top, with four unequal valves closely adhering ; 
the lid consisting of two undivided valves. 
Containing the Lepas striata. 
7, Acasta, Shell fixed in sponge, cylindrical, with 
six valves closely united, seated on a distinct cup- 
shaped base. 
Including Lepas spongiosa. 
8. Pyrgoma, Shell conic, undivided, withan oval 
mouth; the base closed and fixed on a madrepore; 
the lid two-parted consisting of four valves. 
Pyrgoma anglicum, beautiful clusters of this shell 
are found on a madrepore adhering to the rocks at 
low water at Torquay.. 
9. Lepas. Shell seated on a moveable stalk, com- 
pressed at the sides, with five contiguous valves 
of unequal size, the lower side ones larger. 
Includes L, anatifera, L, anserifera or L. sulcata, 
and L, fascicularis. 
10. Scalpellum., Shell seated on a scaly stalk, 
