750 Proceedings of Royal Society of Edinburgh. [sess. 
September. On 17th December a large adult specimen was taken, 
and its umbrella measured 5 mm. in length. Euphysa aurata has 
been taken in Lamlash Bay by Herdman (1880). 
Gemmaria implexa (Alder). (Table I. 7.) 
Zanclea implexa, Hincks, 1868, p. 59, pi. ix. fig. 3. 
Gemmaria implexa, Allman, 1872, p. 289, pi. vii. 
In 1901, single specimens were taken off Little Cumbrae on 
24th and 28th May. This medusa, when liberated from its 
hy droid ( Gemmaria implexa), has two, opposite, tentacles, bearing 
peculiar nematocysts upon long stalks. I have taken at Port Erin 
and in Valencia harbour medusae which have all the characteristic 
features of Gemmaria implexa, but have four perradial tentacles 
instead of two, opposite, tentacles. As specimens were taken at the 
same time, some with two tentacles and some with four tentacles, 
the latter with ripe gonads, I have come to the conclusion that 
the medusa with four tentacles is the fully developed medusa of 
Gemmaria imjplexa. I do not think that they are distinct species, 
as they are similar in every detail except in the number of 
tentacles. 
I have also taken Gemmaria implexa with ripe gonads at the 
two-tentacle stage. But I have noticed in other genera of British 
medusae that the gonads frequently become fully developed and 
ripe before the medusa has reached its maximum growth. 
Gegenbaur (1856) established the genus Zanclea for Zanclea 
costata found at Messina, and this species has four tentacles. 
McCrady (1858) found at Charleston, U.S.A., a medusa somewhat 
similar to a Zanclea, but with only two opposite tentacles. He 
called it Zanclea gemmosa, but suggested the generic name of 
Gemmaria if it should, later on, prove to be a distinct genus. 
Allman (1872) regarded McCrady’s medusa not to be a species of 
the genus Zanclea of Gegenbaur, and therefore adopted the name 
Gemmaria. Hartlaub (1904) mentions the occurrence of a Zanclea 
with four tentacles in Lamlash Bay. 
Description of Gemmaria implexa with four tentacles taken 
at Port Erin on 22nd September 1900 : — The umbrella is 
somewhat globular in shape, about as broad as high, with 
fairly thin walls. Upon the top of the umbrella there is a 
