772 Proceedings of Royal Society of Edinburgh. [skss. 
and called Campanulina repens , but the colonies are more like 
those of Campanulina turrita in form. I first connected this 
medusa with its hydroid when working in the Marine Laboratory 
at Plymouth in 1899, and confirmed my observations at Millport 
in 1902. I found the hydroid growing on mussel shells and 
Laminaria roots attached to the piles of Keppel pier. It was 
placed in an aquarium and soon liberated a few^medusse. 
The medusa is a common British species and is often very 
abundant. It usually appears early in the spring and remains 
until late in the autumn. 
The following species described in Forbes’s monograph are 
probably stages in the life-history of Phialidium cymbaloideum. 
Thaumantias aeronautica , Forbes, p. 44, pi. ix. fig. 3. Four 
tentacles. The first stage in development. 
Lamlash Bay. Herdman (1880). 
Thaumantias quadrata , Forbes, p. 43, pi. ix. fig. 2. Four 
tentacles. This species was found by Forbes at Tarbet, Loch Fyne, 
in the autumn of 1845. 
Thaumantias octona , Forbes, p. 44, pi. viii. fig. 4. Eight 
tentacles. The second stage in development. 
It was found by Forbes at Tarbet, Loch Fyne, in 1845. 
Thaumantias maculata, Forbes, p. 44, pi. ix. fig. 4. Sixteen 
tentacles. The third stage in development. 
Thaumantias globosa , Forbes, p. 46, pi. x. fig. 4. Thirty-two 
tentacles. The fully-grown adult. 
Phialidium temporarium, Browne. (Tables I. 4 ; II. 1.) 
Phialidium temporarium , Browne, 1896, p. 489, pi. xvi. 
In 1901, it was taken from April till November. 
In 1902, it occurred throughout the whole year. 
During the early part of the year up to April only very early 
stages were seen. Adults were taken at the end of May. During 
the summer months, all stages in development, from the earliest to 
the adult, were present in the nets. In the autumn, adults were 
more numerous than the early and intermediate stages. 
The medusa is one of the commonest speeies on the British 
coasts. 
