134 THE ANATOMY OF IXYERTEBRATED AXIilALS. 

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Pig. 28.— I. and II.— Cyancca capVJata (after Van Benedeni). 



I. Two Hyilrce tubce {ScyphMoma stage), exhibiting their ordinary character?, and 



between them two (o, b) which are undergoing fission (Strobi/a stage). 



II. The two Strobilce, a and 6, three days later. In «. tentacles are developed be- 

 neath the lowest of the Ephyr(e, from the stalk of the Strobila, which will persist 

 as a Hydra tuba. 



III. Hair the disk of an Epliyra of AvreJia aurita, seen from the oral face. Tlie 

 Bmall tentacle* which lie between the mouth and the band of circular muscular 

 fibres are inside the somatic cavity, whence sixteen short and wide radial canals 

 extend to the periphery, where they are united by transverse branches. Eight 

 of the radial canals enter the corresponding lobes, and finally divide into three 

 branches: one which enters the peduncle of the lithocyst. and two lateral caeca. 

 Radiating bands of muscular fibres accompany these canals. 



IV. Side view of one f)f the lirhocvsts with its peduncle. The arrow indicates the 

 direction in which the cilia of the exterior work. 



"Eecherclies sur Ui Faunc littorale de Belgique. Polypes." 1866. 



