54 SLABBERIA HALTERATA. 
The bulbs at their bases are more or less triangular, coloured above with bright verdigris 
green, and across the centre with a band of deep orange, below which, on the root as it were 
of the tentacle, is seen a conspicuous and rather large jet-black ocellus. The extremity of 
each tentacle is likewise swollen into a bulb, which is of a rich orange hue. From the centre 
of the sub-umbrella hangs a long and highly extensile peduncle or stomach, capable of being 
contracted entirely within the general cavity, but more usually elongated beyond the length of 
the tentacula. It is of a denser tissue than the other parts, and terminates in a circular 
orifice. The termination is not unfrequently swollen into the shape of a bell. The summit 
projects slightly above the surface of the sub-umbrella. The diameter of the disk does not 
exceed one eighth of an inch. 
This curious Medusa was observed in August, 1836, in Mount’s Bay, Cornwall, where 
ereat numbers of them were taken. It swims with its four tentacles either stretched out 
straight, or at a slight angle, and as if quite stiff, so that they seem with their loaded extremities 
to serve as poisers. The brilliant terminal bulbs, following at equal distances the conspicuous 
ocellated bulbs of their bases, give the creature a very striking aspect, and at first glance 
seem as if they belonged to two Medusz, one of which had partially enveloped the other. 
The Slabberia halterata is a very active, and apparently hardy little animal. This remarkable 
combination of characters, and the features quite peculiar to itself, render it well worthy of 
generic distinction. The position and form of its ovaries indicate a relationship with Thau- 
mantias, whilst the peduncle is that of a Sarsia. It thus links together genera, which, were 
it not for such a connecting form, would seem to be far apart. I have dedicated the genus to 
Martin Slabber, an ingenious Dutchman, who amused himself with the microscope, and 
published an account of his observations at Haarlem, in 1778. He was one of the first to 
direct attention to the minuter forms of Medusze inhabiting the German Ocean, and therefore 
has good claim to preside over a sound generic group. 
Plate VI, f. 1, a, represents Slabberia halterata of the natural size; 1, 6, magnified ; 
1, c, disposition of vessels and ovaries, as seen from above; 1, d, ovary; 1, e, a tentacle 
with its bulbs; 1,,f, proboscis when most dilated. 
