44 Proceedings of the Royal Physical Society. 
the presence of ciliary motion was indicated by the vibratory 
and onward movement of the milky fluid contained therein, 
and it is evident that its function is to supply nutrient mate- 
rial to the powerful muscular tissue of this rapidly swimming 
medusa. 
As far as I know, no similar canals have been detected 
in any of the other Gymnopthalmata. 
(2.) On Acanthohrachia inconspicua, T. S. W. (nov. gen. sp.) 
Umbrella hemispherical, laterally compressed. Peduncle 
four-lipped, short. Lateral canals four ; Tentacles eight ; 
six long, springing from the sides of the margin of the 
umbrella ; two abortive, placed at each end of the mar- 
gin of the umbrella. Otolithic sacs eight, two accom- 
panying each of the tentacular bulbs which do not 
spring from the lateral canals. Extremities of tentacles 
furnished with large prehensile palpocils. 
This Medusa, probably the reproductive phase of a Cam- 
panularian zoophyte, was found in Gran ton Harbour in the 
summer of 1862. It is remarkable for the compression 
of its umbrella, the circular marginal canal of which pre- 
sented an oval contour. The tentacles placed at each end 
of the oval, are very short, and attached along the border of 
the circular canal as far as one of the neighbouring otolites, 
as in Plate I., figs. 2 and 3 a. The long lateral tentacles, 
which are capable of being extended to twelve times the 
depth of the umbrella, are distinguished by the long spinous 
soft palpocils (fig. 4) which spring from their sides, and which 
are capable of being protruded from the ectoderm, and of 
adhering with singular tenacity to any object or smooth 
surface with which they come in contact, over which they 
spread themselves out in an irregular discoid shape, so that 
the animal can hang by its tentacles to the sides of the vessel 
in which it is confined. I have noticed the existence of 
similar exaggerated palpocils on the tentacles of a gymno- 
thalmatous medusa in my paper on Goodsirea mirahilis. In 
both Goodsirea and Acanthohrachia, they are entirely un- 
connected with the existence of thread-cells which are ab- 
sent on those parts of the tentacles from which the palpocils 
