478 MR. E, T. BROWNE ON [Mar. 17, 
Agassiz (1865) has described a medusa, Lizzia grata( = Margellium 
gratum, Haeckel), which has five tentacles in each of the four 
perradial groups and three tentacles in each of the four interradial 
groups. From the specimens collected at Valencia, I have every 
reason for believing that Zizzia grata is the adult form of 
Margellium octopunctatum. 
The early stages of Margelliwm octopunctatum were fairly 
abundant in Valencia Harbour at the beginning of April, but 
decreased in number during May. Most of the specimens taken 
during April and the early part of May had one to four 
medusa-buds upon the stomach. About the middle of May 
specimens were taken with either ova or spermatozoa upon the 
wall of the stomach. The reproductive cells first begin to appear 
upon the perradial ridges on the outside wall of the stomach, and 
as they increase in size they form a mass covering the wall of the 
stomach. As soon as the reproductive cells begin to appear, the 
budding of meduse ceases. The compound basal bulbs of the 
tentacles show little variation in colour, being usually dark brown 
or black. One specimen, however, had reddish-brown bulbs. 
The specimens taken at Valencia resemble those taken at Port 
Erin. I have no doubt that they belong to the same species, and 
as they were taken in a distant locality it may be of interest to 
record some for comparison with those taken at Port Erin. The 
following list shows the number of tentacles in each perradial and 
interradial group of 16 specimens taken at Valencia. It is also 
arranged to show the increase in the number of tentacles during 
the growth of the medusa. 
Perradial 3333 3333 3333 3383 3333 3334 
Interradial 1112’ 3231’ 2299” 9333" 3333’ 3333’ 
Perradial 4843 5334 5344 5433 5444 4454 
Interradial 3333’ 3333’ 3333’ 3333’ 3333’ 3333’ 
Perradial 5454 5553 5554 5555 
Interradial 3333’ 3333’ 3333’ 3333° 
The above series corresponds very closely with a series given in 
the Report on the Isle of Man Medusz. 
The umbrella of the earliest stage is about 1 mm. in length, and 
that of the adult from 3 to 4 mm. 
Not only does the medusa increase the number of its tentacles 
as it grows, but also the number of clusters of nematocysts upon 
the oral tentacles, which are four in number. Though some of the 
specimens taken off the Isle of Man possessed the same number 
of tentacles as Margellium gratum, the clusters of nematocysts 
upon the oral tentacles were fewer in number. Until I had seen 
an exact similarity in every detail, I did not feel justified in placing 
Margellium gratum as the adult of Margellium octopunctatum. At 
Valencia I specially examined the oral tentacles of every specimen 
