CONTENTS. 



ANATOMY AND PHYSIOLOGY OF THE SPONGIAD.E. 



PAGE 



PllEFACE . . i 



OROANO GRAPH Y . 1 



The Spicula . . 5 



The Essential Skeleton Spicula . . 13 



Auxiliary Spicula . 16 



Connecting Spicula . . 16 



Prehensile Spicula . . 20 



Defensive Spicula . 21 



Internal Defensive Spicula . . 28 



Spicula of the Membranes . .39 



Tension Spicula . 39 



Eetentive Spicula . . 42 



Anchorate Spicula . . 45 



Spicula of the Sarcode . 50 



Simple Stellate Spicula . . . .51 



Compound Stellate Spicula . 52 



Spicula of the Ovaria and Geminules . . 57 



Keratode . . 62 



