PORIFERA [sroXGKs]. 



31 



Cahxosa or Flksiiv Si'OXCKS. 



The sponges of this small gnnip fither hiive ui> hard skeleton at CaAo IV. :i. 

 all (ClioniJrosia), or merely scattered stellate spicules {('lunuhiUn). 

 They possess a well-marked rind iiiclusiiig a softer "pith," and tin' 

 canal system is highly developed. 



Chondrosia re/iifoiini^, or the S-'u-Kidney (Case IV. :i), hns a 



Fio. H. 



. ..W 



'W^, 



Section of Geodia sliowinjr crust of ^'lobular spicnlcs, radiatiiifj buniUes of 

 triileiits and needlus, and .small star-shap-jd \\^.^i\\ spicules. Maj,'iiific<l .''O 

 diameters. (After Bowerbank.) 



smooth rounded surface, on which one or two small circular «>.scnlos 

 are present; the mnnerous jxtres are not visihle 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, tiie Carno.sji 

 show many ailiuities with the Kour-iiay Sjionges. 



