74 
SHELL GALLERY. 
Small 
Table 
Case A 
against 
the west 
wall to left 
of main 
entrance. 
BEACHIOPODA. 
The Brachiopoda, though presenting a certain outward resemblance 
to bivalved Mollusca, are quite distinct from this group. They are 
all marine, and all possess a bivalve shell. They grow attached to 
rocks (Fig. 1), usually by a horny peduncle or stalk passing between 
the two valves, or through a foramen in one of the latter ; or, 
peduncle and foramen may be absent, one of the valves adhering by 
Fig. I. 
British Brachiopods (Terebratula and Crania). 
its surface to the rocks ; some species of Lingula live in tubes in the 
sand or mud. They occur at all depths, from shallow water up to 
2900 fathoms, but the largest number of species live at a depth of 
about 350 fathoms. Though found in all seas, the localities whence 
they have been obtained are comparatively few in number ; but 
specimens are usually congregated in considerable numbers, in places 
where they do occur. The surviving species of Brachiopods con- 
