PORIFERA [SPONGESj. 37 



Sponges are sometimes cultivated from cuttings, care being taken High Cases 

 that a portion of the skin is retained in each piece. It takes about }i ^^- ^I^^ 

 seven years for a cubic inch of sponge to grow to a marketable size. 



Attention is directed to the gigantic Luffaria archeri, Neptune's 

 Trumpet (Case II.), from Yucatan, and to the fine fan-shaped 

 specimen of laiitheUa Jf abe/lif or mis hene?ith. it (Case II.) ; the skeleton 

 fibres in these sponges are comparatively thick and cored with a 

 thick pith, those of the bath sponges being solid, or with only a 

 slender core of pith. The specimen of PMjllospongia foUascens 

 (Case 11. 4) shows a curious likeness to a Turbinarian coral, the 

 oscules of the sponge resembling the calicles of the coral ; but it 

 is uncertain whether these resemblances have any real significance. 



Myxospongida or Slime Sponges comprise a small group 

 characterised by the entire absence of a skeleton. HaUsarca forms 

 yellowish-brown slimy crusts on stones. 



[A series of specimens and diagrams illustrating the structure of 

 Sponges is exhibited in an upright table case at the eastern end of 

 the Coral Gallery.] 



