OCEANIA LANGUIDA. 



73 



Fig. 100. 



.101. 



cal pouches, occupying about one fifth of the length of the chymiferous 

 tubes. With advancing age the bell of the Oceania grows more and 

 more flattened, until, in the adult (Fig. 100), 

 it has assumed the shape of a flat segment of 

 a sphere. New marginal capsules are devel- 

 oped at the same time with the rudimentary 

 tentacles, one between every two tentacles 

 in the younger stages ; afterwards there are 

 from two to three capsules between the ten- 

 tacles in the adult. The genital organs of 

 the adult Medusa occujjy more than two 

 thirds the length of the chymiferous tubes ; 

 "when distended with eggs, as in Fig. 101, 

 they hang in irregular lobes from the point 



of attachment, a ; the eggs are quite large ; there is no difference in 



the shape of the male and female genital 

 organs, those of the males are simply some- 

 what darker jjrownish-colored than the ova- 

 I'ies. These Medusae are among the most 

 common on our shores ; they attain their 

 full size during September, Avhen they are 

 frequently met in immense shoals on warm, 

 still, sunny days, collected together for spawning. The young (Fig. 96) 

 make their appearance as early as the end of May. The adult Medusa? 

 assume the most extraordinary attitudes as they float along, carried 

 about by the current ; the disk is so Fig. 102. 



extremely flexible that at times it 

 seems almost as if the Medusa had 

 rolled itself up, as in Figure 102, 

 the tentacles being the strings by 

 ■which the two edges have become fas- 

 tened together. They are exceedingly 

 lazy in all their movements, hard- 

 ly contracting their tentacles when 

 disturbed, contrasting strangely with their former activity in younger 

 stages (Fig. 90), when they move through the water with short, 

 rapid jerks, stopping only to take a more vigorous start. The 

 young Medusa? of Campanularians are all very active, whatever may 

 be the habits of the adults, while in the Tubularians we have gen- 

 erally in the 3'oung Medusa; the temperament of the adult. Young 

 Medusa; of Buugainvillia, Lizzia, and Zanclea are lazy, like the adult ; 



Fig. 100. Adult Oceania laiiji^iiida, natural size 



Fig. 101. Magniliecl view of an ovary, a, aliactinal part of the genital organ. 



Fig. 102. Peculiar attituilc sometimes assumed by these MedusiB. 

 NO. II. 10 



