58 BRITISH HYDROID ZOOPHYTES. 



are somewhat deep, the rim of which, accord- 

 ing to Hincks, is castellated, or squarely 

 toothed. This character we have not observed 

 in the Hastings specimens, although they 

 must, undoubtedly, be referred to the same 

 species. The capsules are borne in the axils 

 of the branches and are about twice the size 

 of the polypite receptacle. 



This hydroid is found plentifully on 

 stones and rocks near low water, very often 

 in flat, exposed situations, and apparently it 

 does not object to muddy surroundings. 



Obelia longissima, Pallas. 



1 specimen dry. 



specimen This species is tall, delicate, and 

 24. attenuated in mode of growth. 



The specimen when living, measured about 

 twelve inches in height. The main stem is 

 simple, with branches thrown out alternately 

 around the axis, at which points, the stem 

 bends slightly outwards, the polypary being 

 ringed above the branching. The rim of the 

 receptacle is squarely toothed as in the last 

 species. The capsule is wider and not so 

 elongated. 



