Spong. 1 
XYII. SPONGER. 
BY 
Professor R. von Lendenfeld. 
CONTENTS. 
Page 
Introduction. 1 
I. Titles.2 
II. Biology. 
1. Morphology and Physiology 
a. General . 5 
b. Canal system .... 5 
c. Skeleton.5 
d. Epithelia, Cuticula . . 6 
e. Sexual Cells, Propagation 
and Development . . 6 
f. Physiology.7 
G. Habits, Bionomics . . 7 
2. Geographical Distribution 
a. General.7 
b. Eaunistic.7 
3. Geological Distribution. . 8 
4. Phylogeny & Classification 8 
5. Methods.10 
Page 
III. Systematic. 
a. Recent Sponges .... 10 
Calcarea 
Homoccela.10 
Heterocoela.10 
Silicea 
Triaxonia 
Hexactinellida . . .10 
Hexaceratina (vacant). 
Tetraxonia 
Tetraxonida 
Tetractinellida . .11 
Lithistida (vacant). 
Monaxonida 
Clavulina . . . .11 
Cornacuspongiae . .12 
Spongillidae . . .12 
b. Fossil Sponges . . . .12 
INTRODUCTION. 
The most important papers on Sponges published in 1899 are (8) in which 
Del age & Herouard treat of Sponges in general; (7) in which the 
discussion on the position of Sponges in the animal kingdom carried on at 
the Cambridge Zoological Congress is given; (10) in which Evans de¬ 
scribes the larva and metamorphosis of Spongilla and publishes notes on 
mitosis, systematic position etc.; (33) in which Schulze gives an account 
of the Collar-cells of the Hexactinellida ; and the systematic papers by 
Schulze on the Hexactinellida of the “Albatross” expeditions (34) and by 
Thiele on the Tetraxonia of Celebes (41). 
