490 MR. E, ‘I. BROWNE ON [Mar. 17, 
variabile, Haeckel, consists of several distinct species, one of them 
being Phialidium (Eucope) variabile (Claus), a species probably 
identical with Phialidium buskianum (Gosse). 
Béhm (1878) has given Campanulina acuminata as the name 
of this species, which he has described and figured in the adult 
stage, taken off Heligoland. Béhm has not reared the medusa 
from the hydroid, and does not show that the young medusa from 
the hydroid Campanulina acuminata develops into the medusa 
which he has described under the same name in the adult condition. 
No doubt the young meduse from the hydroid Campanulina 
acuminata do develop into one of the species belonging to the 
genus Phialidium. For this reason I have not used Bohm’s specific 
name of the adult medusa, as it may not belong to the hydroid 
Campanulina acuminata. 
I give here a description of the various stages of Phialidiwn 
temporarium :— 
lst Stage. Four tentacles. (Plate XVII. fig. 4.)—The earliest 
free-swimming stage, which I have seen, was taken at Valencia 
in May 1895. Umbrella bell-shaped, about ? mm. in length and 
width. Four perradial tentacles and four interradial tentacle-bulbs. 
Eight marginal vesicles with a single otolith in each. Tentacle-bulbs 
and the basal bulbs of the tentacles yellowish brown. Stomach 
short; mouth with four short lips. In one specimen the apical 
stalk, or the prolongation of the stomach into the substance of the 
umbrella, was still present, indicating that the medusa had not 
long been liberated from its hydroid. The generative organs form 
a minute round or oval swelling, one on each radial canal, about 
halfway down. 
2nd Stage. Light tentacles—The interradial bulbs belonging to 
the first stage develop tentacles, and a little later some of the 
adradial bulbs begin to appear. It may be sometimes difficult to 
distinguish at this stage this species from Phialidium cymbaloideum, 
as both possess eight marginal vesicles, but in the latter species I 
have always seen at least two otoliths in all the vesicles. In 
Phialidium temporariwm occasionally two otoliths may be present 
in one vesicle, but never in all the vesicles. 
3rd Stage. Siateen tantacles and 16 or more marginal vesicles.— 
The adradial tentacles appear in no definite order, so that one 
quadrant sometimes contains more tentacles than another. The 
marginal vesicles also increase in number, one is always present 
between every two tentacles, occasionally two may be present. 
The umbrella grows faster in width than in length, being about 6 
to 7 mm. in width and 4 to 5 mm. in length. The generative 
organs grow downward towards the margin and become oval- 
shaped. The colour of the generative organs shows slight variations, 
usually yellowish brown, occasionally reddish brown. 
Adult Stage. (Plate XVII. figs. 5 & 6.}—The largest specimen 
which I have measured was 21 mm. in width and 11 mm. in length, 
with 38 tentacles. Two or three marginal vesicles between every 
