52 
summit. e@ pa’ 
hibit the modifications which the hydrospires undergo in passing through:— 
: tremites with broad ambulacra. 4. Pentremites with single 
tubes. 5. ‘ ; a convoluted - te to the centre 
: convoluted plat. 7. Ambulacral canals of a starfish with the doubly convo- 
or 
Lt. Billings on the structure of the Crinoidea, ete. 
SSSR SS SS 
HII) 
i 
N 
q 
bad 
Pay NIs)) 
PH 
mt 
avanpnnnyeney 
yyy 
df) 
iy 
A, 
r 
shed *s Ss comppbiigeal ae. 
