PORIFERA [SPONGES]. 
31 
Oarnosa or Fleshy Sponges. 
The sponges of this small group either have no hard skeleton at Case IY. 3. 
all ( Chondrosia ), or merely scattered stellate spicules ( Chondrilla ). 
They possess a well-marked rind inclosing a softer “ pith,” and the 
canal system is highly developed. 
Chondrosia reniformis, or the Sea-Kidney (Case IV. 3), has a 
Fig. 14. 
Section of Geodici showing crust of globular spicules, radiating bundles of 
tridents and needles, and small star-shaped flesh spicules. Magnified 50 
diameters. (After Bowerbank.) 
smooth rounded surface, on which one or two small circular oscules 
are present ; the numerous pores are not visible to the naked eye. 
The sponge, being devoid of a hard skeleton, shrinks greatly when 
dried, but swells up again on being immersed in fluid. Apart from 
the absence of trident spicules and of a hard skeleton, the Carnosa 
show many affinities with the Four-Ray Sponges. 
