24 EDWARD T. BROWNE. 
on liberation from its Hydroid, either has only four perradial tentacles or eight 
(four perradial and four interradial) tentacles. The tentacles which appear later 
develop in pairs and in the order shown by these figures—4, 3, 2, 1, 2, 3,4. Some 
of the specimens have the groups of tentacles quite close together, which gives the 
appearance of the tentacles being uniformly distributed round the margin of the 
umbrella; but their position is entirely due to the contraction and shrinkage of 
the jelly, and this is especially noticeable in the specimens preserved in alcohol. The 
tentacles are solid, and the endodermal core is in direct contact with the endoderm of 
the circular canal. The lower side of the basal portion of the tentacles in each group 
is covered with a layer of ectoderm containing nematocysts. There is no well-marked, 
conspicuous compound basal bulb common to each group of tentacles, such as occurs 
in Margelis or Chiarella, The tentacles in a semi-contracted condition show at their 
distal ends conspicuous circular bands of nematocysts (fig. 3), but these bands seem to 
disappear when the tentacles are fairly well expanded, and the nematocysts become 
evenly distributed. There is not the slightest trace of ocelli at the base of the 
tentacles. 
Famity CLADONEMID. 
Prof. Haeckel, in 1879, collected together various genera of Anthomeduse ° 
having either tentacles with branches, or tentacles bearing appendages armed with 
nematocysts, or tentacles provided with stalked cnidophors, and placed them in the 
family Cladonemide. The character of the family has remained practically unaltered 
to the present day, but the genera have slightly increased in number and have heen 
revised and re-classified by Mr. R. T. Giinther (1903) and by Dr. Hartlaub (1907), who 
adopts Mr. Giinther’s classification of the genera. 
The Cladonemide are divided into two sub-families :— 
1. Pteronemide with unbranched tentacles having filaments with nematocysts, 
or tentacles armed with cnidophors. 
Genera—Preronema, Zanclea, Halocharis, Mnestra, Ctenaria. 
2. Dendronemide, with branched tentacles; one branch terminating in a 
sucker or adhesive disc, the other branch or branches provided with 
batteries of nematocysts. 
Genera—Fleutheria (Clavatella) Zancleopsis, Cladonema, Dendronema. 
In accordance with the classification at present in vogue for the Anthomeduse, 
the new Antarctic Medusa which I have described under the name of Catablema 
weldoni on page 13 should have been described as a new genus of the Cladonemide 
and not placed in the genus Catablema of the Tiaride. Although this Medusa -has 
tentacles which bear appendages or filaments armed with a terminal battery of 
nematocysts, I do not consider that it has any connection with the Cladonemide. 
The structure of the gonads, the basal bulbs of the tentacles, and the mouth are 
