1904 - 5 .] Report on Medusae found in Firth of Clyde. 
757 
The medusae on liberation resembled Allman’s figure, and they 
reached the adult stage in about seven to ten days. 
Description of the adult : — The umbrella is somewhat oval in 
shape, a little longer than broad and moderately thick. Velum 
very broad. The stomach is cylindrical in shape, and is about 
as long as the cavity of the umbrella, but does not extend beyond 
the velum. The mouth is circular. Four radial canals. The 
gonad forms a swelling round the whole stomach, extending from 
its base nearly to the mouth. Four tentacles, with circular 
clusters of nematocysts and an extra large terminal cluster. The 
basal bulbs of the tentacles are large, and oval in shape ; upon 
each one there is a large circular ocellus. 
Colour. — Stomach and basal bulbs reddish-brown. Ocelli black 
in the early stages, but crimson in the adult. 
Size. — Umbrella about 3 mm. in length and 2 mm. in width. 
Sarsia gemmifera, Forbes. (Table I. 21.) 
Sarsia gemmifera , Forbes, 1848, p. 57, pi. vii. 
In 1901, two specimens were taken on 22nd July. It suddenly 
became fairly common on 30th September, but was not seen after 
2nd October. The sudden appearance and disappearance were 
probably due to a small shoal drifting up the Clyde from the 
south. 
In 1902, it was not seen. 
The specimens taken on 30th September had two to four 
medusa-buds upon the long manubrium. The largest bud was 
usually at the top of the series. After the medusoids are liberated 
a second series of buds is developed, and these are situated on the 
stalks of the first series. The young medusae at the time of their 
liberation have also buds just beginning to develop. All the 
specimens had a gonad surrounding the stomach, which is at the 
end of the long manubrium. No females were seen. The 
presence of a gonad on the stomach of Sarsia gemmifera and 
Sarsia prolif era indicates that these medusae have a hydroid stage 
in their life-histories, but up to the present the hydroids remain 
unknown. 
