DYSMORPHOSA. 



163 



DYSMORPHOSA Phil. 



Dysmorphosn Piiii..; in Archiv f. Nat., p. 37. 1842. 

 Podocort/rie Saks. Fauna Lit., p. 4. 1«46. 



Sars has traced the development of a Medusa from Podocoryne 

 Crimea which is very closely allied to Dysmorphos^d fuh/io-fois here 

 lio-ured. It corresponds, in its younger stages, while still attached to 

 the proboscis of its parent, to the different stages of our Medusa, in the 

 number, arrangement, and order of appearance of the tentacles, so com- 

 pletely, that I have referred it to the genus Dysmor])hosa of Philippi, 

 considered by Sars as identical with the Hydroid from whicli his 

 Medusa was developed. This identification is the more prol)able, as 

 Krohn has given us a complement to the observations of Sars on the 

 adult Medusa^, and traced the budding from the proboscis in exactly 

 the same manner as it is here given. The Lizzia figured by Claparede 

 in the tenth volume of Siebold u. Kcilliker's Zeitschrift, in which he has 

 also traced the budding from the proboscis, appears to be identical with 

 the Podocoryne carnea of Sars. 



Dysmorphosa fulgurans A. Agass. 



This Medusa (Fig. 259) is sometimes so abundant that the whole sea, 

 when disturbed, is brilliantly lighted by the peculiar bluish phosphores- 

 cent color which they give out. Their great number is easily accounted 

 for by their mode of reproduction and by its rapidity. Young Medusae 

 are formed by budding on the upper extremity of the proboscis (Figs. 

 259, 260), tmd their development takes place in the course of three or 



Fifr. 259 



four days ; from three to four Medusae develop at the same time ; the 

 Medusae buds of the third generation are already forming, while the 

 second is still attached. (Fig. 260.) The young Dysmorphosa has at 

 first four tentacles, the middle set developing later ; there are only four 

 oral tentacles, quite long and slender, and an accumulation of pigment- 



Fig. 259. Adult Dysmorphosa ; magnified. 



Fig. 260. Magnified proboscis, showing young Medusae of the second and third generations. 



