176 



ANTIIOZOA ASTEROIDA. 



Fig. 38. 



pend, hanging loose iu an abdominal cavity placed underneath the 

 fleshy cylindrical stomach, and continuous with the aquiferous canals.* 



The Polype-cells are 

 oval, placed just under 

 the skin, and are the 

 terminations of the 

 long aquiferous canals 

 which run through the 

 whole polypidom. (Fig. 

 38.) These canals di- 

 vide in their course 

 into branches that di- 



verge towards the cir- 

 cumference where they 

 dilate into the cells ; 

 they have strong 

 cartilaginous, perhaps 

 muscular, coats ; and 

 are filled with a much 

 less consistent matter 

 than that of the body 

 of the polype itself. It appears, from this disposition of the tubes, 

 that many polypes communicate together and form a compound ani- 

 mal, but that all the polypes of the same polypidom do not commu- 

 nicate directly by their medium. The space between the tubes is oc- 

 cupied by a loose fibrous net -work, and the threads being a little more 

 crowded at particular places, they form lozenge-shaped compartments 

 within which are smaller meshes ; and the interstices of the whole 

 are filled with a transparent gelatine, in which numerous crystalline 

 irregular spicula lie immersed. These spicula are mostly in the form 

 of a cross and toothed on the sides, but they have no organic connec- 

 tion either with the reticular fibres or with the tubes ; they are cal- 

 careous, for if a portion of the zoophyte is immersed in a mineral 



* A classical friend on seeing the specimen from which our figure was taken in 

 full expansion, when it is translucent and permits a view of the interanea, was re- 

 minded of the following lines : 



" In liquidis translucet aquis ; ut eburnea si quis 



Signa tegat claro, vel Candida lilia, vitro." 

 " salientia viscera possis 



Et perlucentes numerare in pectore fibras." 



Ovid. Met. vi. ,354 and 390. 



