DTSMORPHOSA. 



75 



mained connected with the Hydroid from which it arises, a rather 

 large Tubularian, usually growing singly (Fig. 104), and of a 

 deep orange-red in color. But at this stage of its existence it 

 frees itself, and leads an independent life hereafter, swimming 

 about with a quick, darting motion. In the account of the Na- 

 nomia, the homology between its scale, or abortive Medusa, and 

 the Hybocodon, is traced in detail, and I need only allude to it 

 here. Though this Medusa is so peculiar in appearance, the 

 Tubularian from which it is derived is very like the Tuimlaria 

 Covthovyi, already described. This is one of the instances before 

 alluded to, in which closely allied forms give rise to very dissimi- 

 lar ones, or, as in many cases, the very reverse of this takes place, 

 and closely allied forms arise from very dissimilar ones. 



Dytrmrphosa. {Dysmorphosa fidguram X. Xa.) 



Besides the budding at the base of the tentacle, as in Hyboco- 

 don, we find another mode of development among Hydroid Me- 

 dusae, viz. that of budding from the proboscis. One of our most 

 common little Jelly-fishes, the Dysmorphosa (Fig. 105), to which 

 we owe the occasional blue phosphorescence of the sea, so brilliant 

 at times, buds in this manner. Fig. 105 represents an adult Dys- 



Fig. 106. 



Fig. lOS. 



morphosa, on the proboscis of which may be seen three smaU buds 

 in different stages of development. In Fig. 106 the proboscis is 

 more enlarged, showing one of the little Jelly-fishes similar to 

 the parent, just ready to drop ofF. We need not wonder at the 



Fig. 105. Dysmorphosa seen in profile ; magnified. 



Fig. 106. Magnified proboscis of Dysmorphosa with young Medusse budding from it. 



