BIGELOW: MEDUSAE FROM THE MALDIVE ISLANDS. 251 
DESCRIPTION OF THE SPECIES. 
I HYDROMEDUSAE. 
Dipurena fragilis. 
Dipurena fragilis Mayer, A. G., 1900. Bull. Mus. Comp. Zool., vol. 37, p. 28, 
plate 17. 
This Medusa, if not identical with Dipurena fragilis Mayer, from the Tor- 
tugas, is very closely allied to it. It appears to differ from it in being color- 
less, and in having the swollen regions on the proboscis much less prominent. 
The fact that only one specimen was taken makes me hesitate to separate it 
specifically. 
January 2. Suvadiva atoll, near Dandu island; surface. 
The occurrence of Dipurena in the Indian Ocean is of interest, since this 
genus has never been taken in the tropical Pacific, though in the tropical 
Atlantic and Mediterranean it is represented by numerous species. 
Euphysa tetrabrachia, sp. nov. 
Plate 1, Fig. 1. 
I have rather doubtfully referred the present species to Euphysa, to which 
genus it shows more resemblance than to Corymorpha. The bell is four mm. 
high by two and one half broad ; pear-shaped, with a low and broad apical 
projection, and it is perfectly symmetrical. The single long tentacle is well 
developed, and is about four times as long as the bell is high. The other 
three, instead of being mere rudiments, are of considerable size, about one 
third as long as the bell height, and are equally developed. All four are 
ringed with nettle cells, about three rings on each of the short, and six or 
eight on the long, tentacle. 
There is an ocellar bulb borne at the base of each tentacle. The proboscis is 
flask-shaped, its upper portion distended by the swollen half-spherical masses 
of gonads, arranged in eight fairly distinct rows. The mouth hangs below the 
bell opening, and bears no lips. 
The bell is colorless and very transparent, the gonads brownish yellow, the 
proboscis slightly pinkish, and the ocellar bulbs and rings of nettle cells rose 
pink. 
One specimen, January 7, in Suvadiva atoll. Surface. 
The generic position of this very distinct species seems doubtful. It agrees 
with Euphysa in the symmetry of the bell, and in the arrangement of the 
gonads, which correspond very well to the figures of Euphysa virgulata, given 
by Alexander Agassiz (North American Acalephae, 1865, p. 190, fig. 317). 
