ACALEPELE. 219 



these very enigmatical beings were worthy of serious study the 

 study of subsequent naturalists, such as Cuvier, De Blainville, 

 Ehrenberg, Brandt, Makel-Eschscholtz, Sars, Milne Edwards, Forbes, 

 Grosse, and other modern naturalists, who have demonstrated what 

 richness of structure is concealed under this gelatiniform and simple 

 structure in the Medusae ; at the same time they have revealed to us 

 most mysterious and incredible facts as connected with their meta- 

 morphoses. 



Among the Medusae proper, the most common are Aurelia, Pelagia, 

 and Chrysaora. In the latter, G. Gaudichaudi (Fig. 88), the disk 

 is hemispherical, festooned with numerous tentacles, attached to a 

 sac4ike stomach, opening by a single orifice in the centre of the 

 peduncle, with four long, furbelowed, unfringed arms. G-audi- 

 chaudi's chrysaora is found round the Falkland Islands. The disk 

 forms a regular half- sphere, very smooth, and perfectly concave, form- 

 ing a sort of canopy in the shape of a vault. The circle which sur- 

 rounds it is divided into sections by means of vertical lines, regularly 

 divided, of a reddish-brown colour, which forms an edging to the 

 umbrella-like disk. Twelve broad regular festoons form this edging. 

 From the summit of these lobes issue twelve bundles of very long, 

 simple, capillary tentacles, of a bright red. The peduncle is broad 

 and flat, perforated in the middle, to which are attached four broad 

 foliaceous arms. 



EHIZOSTOMA. 



The Medusae which bear the name of Rhizostoma have the disk 

 hemispherically festooned, depressed, without marginal tentacles, pe- 

 duncle divided into four pairs of arms, forked, and dentated almost to 

 infinity, each having at their base two toothed auricles. Such is 

 liliizostoma Cuvieri of Peron (Fig. 89), the disk of which is of a bluish- 

 white, like the arms, and of a rich violet over its circumference. This 

 beautiful zoophyte is found plentifully in the Atlantic, living in flocks, 

 which attain a great size. It is common in the month of June on the 

 shores of the Saint Onge ; in August on the English coast ; and along 

 the strand of every port in the Channel they are seen in the month of 

 October in thousands, where they lie high and dry upon the shore, 

 on which they have been thrown by the force of the winds. 



