THE LOWER FORMS OP LIFE. 97 



Bhizostoma, are placed by many systematists in the next and last 

 order, the Lucerniadae. 



Among the covered-eyed species of Medusae, two species are very 

 common on our shores. First, Aurelia aurita; this when seen 

 floating through the water is readily distinguished by four crescent- 

 shaped purple markings, which are discerned through the gelatinous 

 disc or umbrella. This species is very abundant all along our 

 coasts, sometimes, as Forbes remarks, impeding the progress of boats. 

 I need not figure it, as any one may get it for himself. It does not 

 sting. 



The other common species on our coasts, Cyanea capillata, does, 

 however, sting severely. It is distinguished by its flatter disc, " bf 

 a pale yellow colour, deeply scalloped at the margin into sixteen 

 quadrate lobes, between each pair of which in a deep notch is a 

 conspicuous pedunculated ocellus. Eight brownish rays proceed 

 towards these ocelli from a circle of reticulated, quadrate, brown 

 markings, giving the whole disc a beautifully stellated appearance, 

 which depends on the organs on the sub-umbrella, which is fur- 

 nished with long plicated and furbelowed membranous arms and 

 fasciculi of extremely extensile stinging filamentary tentacles" 

 (Forbes). 



The Medusa which I illustrate at Fig. 118 (p. 93) is a species which 

 has been taken occasionally on our shores, but is well known to those 

 who have sailed on the coast of Italy, where it looks, owing to its 

 phosphorescence, like a ball of fire in the water. It is a very beau- 

 tiful creature. The disc is of a rich rose colour speckled all over, 

 especially at the sides, with orange-coloured warts. Its margin is 

 divided into sixteen lobes, from beneath eight of which spring eight 

 long tentacles, while in the remaining grooves are eight red covered 

 and stalked ocelli. 



The species as shown by Fig. 119 (p. 94) deserves one or two 

 remarks. As a rule, the appendages which hang down from the 

 centre of the umbrella are connected with the polypite, whose 

 mouth they cover and provide with food. In Ehizostoma Cuvieri, 

 however, the arms end in distinct polypites, each having a small 

 opening or mouth at its extremity ; this is the commencement of 

 a canal which, after dividing freely in the arms, terminates in a 

 large stomach which is covered in by the second tier of fringes in 

 the figure. It has no other digestive apparatus. The stomach is 

 not yet even free, but remains, as in the Hydra, a hollow in the 

 substance of the polypite, with its inner and outer skin. 



There are six genera of "covered-eyed" Medusae described as 

 occurring on our sea-shores, but the number of species is only eight 

 or nine. Chrysaora hysoscella has curious ribbon-like appendages, 



H 



