1896.] BRITISH HYDROIDS AND MEDUS. 473 
Part I1—MEDUSZ WITHOUT OR WITH UNKNOWN 
HYDROID FORMS. 
These Meduse are arranged according to Haeckel’s ‘ System der 
Medusen.’ 
ANTHOMEDUSZ. 
Fam. CODONID &. 
DIPURENA HALTERATA (Forbes). 
Slabberia haltercta, Forbes (1848); Cocks (1849). 
Dipurena halterata, Haeckel (1879); Browne (1895). 
I have occasionally met with one or two specimens of this 
interesting medusa. 
I saw one specimen at Plymouth on 25th September, 1893. 
The specimen was unfortunately in a bad condition, the umbrella 
being turned inside out. The basal bulbs of the tentacles were of 
a dark brown colour with a single deep crimson ocellus. At the 
free end of each of the four tentacles there was a very large knob- 
like cluster of nematocysts, and the upper half contained a dark 
brown pigment. 
A single specimen was taken at Valencia on 10th April, 1895. 
Umbrella about 1 mm. in length. 
Forbes describes and figures the gonads as slight swellings upon 
the radial canals. This statement requires confirmation. Haeckel, 
however, has taken a specimen at Jersey, which corresponded to 
Forbes’s description, except that the gonads were upon the 
manubrium. Haeckel describes three swellings on the manubrium, 
one above the other, filled with sperm, the lowest swelling reaching 
nearly down to the mouth. 
Disrrizurion. Jersey, Haeckel, 
England—Plymouth, 2. 7, B. Falmouth, Cocks. Mounts Bay, 
Forbes. Isle of Man, Browne. 
Treland—Valencia Island, #. 7. B. 
Drpevurena, sp.? (Plate XVI. fig. 2.) 
During my visit to Plymouth in September, 1895, I obtained 
upon the 10th two specimens of a medusa which certainly belongs 
to the genus Dipwrena. I regard them as early stages on account 
of medusa-buds being present upon the stomach. I have already 
shown in the cases of Amphicodon fritillaria, Margellium octo- 
punctatum, and Lizzia blondina, that it is a characteristic feature of 
the young stages to bud off medusz, and in the adult stage to have 
gonads upon the stomach. I believe that Codoniwm gemmiferum and 
Sarsia prolifera, now regarded as distinct species, will be ultimately 
proved to be only early stages of other known species. 
I have not yet been able to trace these early stages of Dipurena 
