PLATE XXIX. 
PAGE 
Theonella swinhoei, . . . .284 
Figure 1. Sponge ; nat. size. Lateral view. 
2. Sponge, seen from the oscular end ; nat. size. 
3, Vertical median section of the sponge ; nat. size. 
„ 4-8. Spicules — 
Figs. 4, 4a-4e. Various forms of phyllo- 
trisenes; x 73. 
„ 5, 5a-5c. Microstrongyles ; fig. 5, 
a young form ; figs. 5a-5c, 
various forms of fully grown 
spicules; x 500. 
„ 6, 6a-6e. The strongyle ; fig. 6, the 
usual form, x 95; figs. 6a, 6l>, 
ends of strongyles, showing the 
enlargement of the axial rod, 
X 360; fig. 6c, an example 
with tylote ends, x 95 ; fig. 6d, 
the tylote ends, more highly 
magnified, x 360. 
Figs. 7,7a. Tetracrepid desmas ; x 73. 
„ 8, 8a, 85. Young forms of the 
desma; x 430. 
