238 
Fig. 
Fig. 
Fig. 
Fig. 
LIVERPOOL BIOLOGICAL SOCIETY. 
. Vertical section through the massive form of Cliona 
celata, Grant (X 3). 
PLATE XII. 
. Cliona celata, Grant, not quite one-half natural size. 
Puate XIII. 
. A portion of the choanosome of Secriola compacta, 
Hanitsch, showing chamber-system, strand of 
‘problematic cells’’ Gn longitudinal section), 
and cystenchymatous tissue (xX 250). 
. Transverse section through a strand of ‘‘ proble- 
matic cells” of Seiriola compacta, with cys- 
tenchymatous tissue around it (X 250). 
. Section through the choanosome of Sezrzola com- 
pacta, showing the branching of the strands of 
‘‘ problematic cells” (x 50). 
. Portion of fibrous layer of Sezrzola compacta, situated 
between ectosome and choanosome (X 250). 
PLATE XIV. 
. Vertical section through the upper portion of the 
ectosome of Stelletta collingsi, Bowerbank. The 
encroaching Sycandra ciliata (m the upper left 
corner of the plate), shown diagrammatically, 
(xX 200). 
. Spined portion of a prionorrhabd (x 800). 
. a, chiaster (X 800); 0, c, and d, forms of oxyaster 
(x 400). 
. a, protriena; }, dichotrizena (xX 60). 
PLATE XY. 
. Portion of transverse section through Leucaltis 
umpressa, N. sp. (X 80). 
. Two specimens of Leucaltis ¢mpressa, natural size. 
. a, b, c, and d, triacts and tetracts of the body-wall 
(x 150); 7, gastral tetract (x 150). 
