190 HISTORY OF BRITISH ZOOPHYTES. 
Professor Van der Hoven thinks otherwise; and so does 
Dr. Johnston, and so also, may we add, do we, and we have 
seen more than one young one on the body at the same time, 
not at Blainville’s “ point de jonction de la partie creuse et 
de celle qui ne l’est pas,” but one of them nearer the tail, 
and the other nearer the tentacula. 
2. Hypa VULGARIS. 
Hab. Ponds and slowly running streams. 
This is about the same size as H. viridis, which it also 
resembles in form, but it differs from it in colour, being of 
an orange colour, or sometimes more of a brown or even 
bright red tint, the brightness of the tint depending on the 
nature of the food. The tentacula are rather more nume- 
rous and longer than in the former. 
3. Hypra arrenvata, Dr. Johnston. 
Hab. Ponds, Yetholm Loch, Roxburghshire, Dr. Johnston. 
“A larger animal than the former, and comparatively rare, 
less sensible to external impressions, and of a more gracile © 
form. Its colour is a dilute olive-green, with paler tenta- 
cula, which are considerably longer than the body, and 
hang like silken threads in the water, waving to and fro, 
without assuming that regular circular disposition which 
they commonly do in HZ. viridis.” (Dr. Johnston.) 
