62 ZOOLOGY 
The position of the tentaculocysts, however, always marks the 
position of the eight original lobes. 
Aurelia is a Seyphomedusan very commonly met with round 
If the adult 
our coasts swimming at the surface of the sea. 
medusa be examined, it will be seen that the original four-lobed 
chamber of its Scyphistoma has given off a number of branch- 
ing enteric canals which ultimately open into a circular vessel. 
Between these canals the aboral and oral endoderm has given 
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Fic. 43.—Aurelia aurita. 
5. An adradial canal. 
1. Mouth. 
2, Cireumoral perradial processes. 8. The circular canal. 
3. Tentacles on the edge of the umbrella. 9. Marginal lappets hiding tentaculo- 
cysts. 
4, One of the branching perradial canals. 
There are four of these, and four 11. Gastral filaments. 
similar interradial canals. 
rise by conecrescence to the endodermal lamella (Fig. 39). 
Hight adradial canals are given off from the central chamber 
between these branching canals, and these pass directly to the 
circular canal without giving off any branches. 
The mouth of Awrelia is surrounded by four perradial 
