1904 - 5 .] Report on Medusae found in Firtli of Clyde. 761 
and intermediate stages. No full-grown adults were seen. About 
twenty specimens were collected in Lamlash and Etterick Bays. 
Nearly half of these had a cone-shaped crown on the top of the 
■umbrella, variable in shape, either pointed or rounded at the apex. 
The remainder had a globose crown, which varied, greatly in size. 
The specimens also showed variation in colour, being either pale 
yellowish-brown, or pale brown, or reddish-brown. 
This medusa is liberated from a Perigonimus, probably the 
species commonly called Perigonimus repens , and starts its free- 
swimming life with two tentacles, many more developing as the 
medusa grows. Most of the specimens in the Clyde had four to 
eight tentacles, and a few had twelve tentacles. A fully-grown 
adult has about forty tentacles. 
The hydroid Perigonimus repens has been found in the Clyde, 
off the west coast of Arran. 
The following species, -which have been described and figured in 
Forbes’s monograph, are regarded by me as stages in the life- 
history of Tiara pileata. 
Oceania turrita , Forbes, p. 28, pi. ii. fig 2. Four tentacles. 
Oceania octona (Fleming), Forbes, p. 27, pi. ii. fig 3. Eight 
tentacles. 
Oceania episcopalis , Forbes, p. 27, pi. ii. fig. 1. Twelve 
tentacles. 
Order — LEPTOMEDUSiE. 
Dipleurosoma typicum, Boeck. (Tables I. 14; II. 16.) 
Dipleurosoma typicum , Browne, 1898, p. 826, pi. xlviii. 
In 1901, it was first seen on 5th June and disappeared after 
:20th July. Only a few specimens taken. 
In 1902, a specimen was taken on 11th June, and another on 
18th June. Two were taken on 15th July. 
This species is at times very abundant in Valencia harbour. 
Irene pellucida (Will). (Table I. 26.) 
Geryonia pellucida , Will, 1844. 
Irene pellucida, Claus, 1881, p. 102, taf. iii. figs. 21-30. 
In 1901, a single specimen was taken on 30th September. 
