180 ZOOPHYTES. 



Amph'tfrite ventilabrum, which always rises erect from some solid substance 

 if attaining large dimensions. Such specimens are generally of very irre- 

 gular* growth, and especially of variable thickness. Here vivid orange ova 

 lay at the bottom of the flesh of the Lobularia, almost close to the dark 

 tube invested by it, though the specimen itself was pure white. 



Returning to the colour of this product : some orange and some white 

 Lobularia are occasionally found intermixed in the same group. 



Among several thus originally constituting a group, I remarked two 

 that had been accidentally rent across, perhaps in removal from the sea. 

 The whole interior of one of them was perfectly white, but covered as if 

 by an orange coating a line thick. The other resembled it, being of simi- 

 lar character, but the exterior orange coating was thinner. This separa- 

 tion was only of colour not of substance, the orange and the white portion 

 being incorporated together. 



A group of the faintest carmine, once occurred on the shell of a 

 Venus Islandica. This, which is one of our largest Scotish bivalves, serves 

 frequently as a foundation for other subjects. 



The orange ova are grey in an early stage, and seem to be attached 

 to the lower part of the receptacle of the hydra. Some are solitary, others 

 composing groups of five, six, seven, or more, as approaching maturity, when 

 their vivid colour affords a fine contrast with the white of the Lobularia 

 as they rise towards the surface. Next they are produced free. 



At first the nascent hydra is single ; it gains one companion, then 

 two, three, or a greater number. 



But it is plain that the earlier generations are overwhelmed, and their 

 site obliterated, by those of later origin. 



The Lobularia is the prey of the Doris Hombergii, therefore obtain- 

 ing recent specimens is of some consequence to the naturalist desiring the 

 preservation of that animal for permanent study. The food of the Doris 

 tribe can be seldom discovered. 



This product is commonly rooted on hard solid substances, though 

 specimens of smaller size grow also on the marine Alga? and the Corallines. 

 But above all, the tube of the Ampkitrite ventilabrum, is most profusely 

 invested by it in a single stratum and otherwise. Among a multitude of 



