316 HYDKID^E. 



a stem or pedicel. It is traversed by a narrow canal, 

 which terminates below, according to the observations of 

 Baker, in a small opening. The arms are comparatively 

 few in number, but are amazingly extensile. 



This is a very beautiful and interesting species, and 

 apparently less common than the preceding. 



Hab. Still waters ; rare : near London (Mantell) : near 

 Belfast (Templeton): the Avon, Guy's Cliff (T. H.). 



4. H. ATTENUATA, Pallas. 



HYDRA ATTENUATA, Pall. Elcncli. 32; Johnst. B. Z. 12.'3, pi. xxix. fig. I. 

 FALLENS, Turf., Gmel. iv. 692. 



POLYPITES " light oil-green, the body attenuated below, 

 with pale tentacula longer than itself" (Dr. Johnston}. 



H. ATTENUATA, according to Johnston, is larger than H. 

 vulgaris, and " of a more gracile form. Its colour is a dilute 

 olive-green, with paler tentacula, which are considerably 

 longer than the body, and hang like silken threads in the 

 water, waving to and fro without assuming the regular 

 circular disposition, which they commonly do in the H. 

 viridis" 



I know nothing of this species. Fleming ranked it 

 under H. vulgaris ; but Johnston, after " long, continuous 

 observation of individuals in confinement," was convinced 

 of its distinctness. 



Hab. Yetholm Lough, Roxburghshire (Johnston). 



