BIGELOW: MEDUSAE FROM THE MALDIVE ISLANDS. 26d 
The remainder of the Jower surface of the disc, between the central polypite 
and the tentacular zone, is completely covered by the long, slender feeding 
and reproductive polypites, bearing at their bases clusters of Medusae in all 
stages of development. These Medusae agree very well with the figures given 
by Alexander Agassiz for Porpita linneana. (Mem. Mus. Comp. Zodl., 
vol. 8, no. 3.) Scattered among the reproductive polypites are a few of larger 
size, which seem to be sterile. Their heads are rounded and surrounded by 
four clusters of nettle cells. Our preserved specimens are unfortunately too 
imperfect to allow of histological investigation, so 1 have been unable to trace 
the number or position of the tracheae. | 
The characteristic external features of this species are: first, its intense Prus- 
sian blue color ; second, the large size and extreme flatness of the disc; third, 
the shortness of the tentacles, and fourth, the great length of the feeding and 
reproductive polypites. 
Diphyopsis appendiculata Acassiz and Mayer. 
Diphyes appendiculata Eschscholtz, 1829, Syst. der Acalephs, p. 188, taf. 12, fig. 7. 
Diphyes appendiculata Huxley, 1859, Oceanic Hydrozoa, p. 34, plate 1, figs. 2-2c. 
Diphyopsis appendiculata Agassiz, A., and Mayer, A. G., 1899, Mem. Mus. Comp. 
Zool., vol. 26, no. 5, p. 160, plate 9. 
A species of Diphyopsis, apparently identical with the Diphyopsis appendi- 
culata of Agassiz and Mayer, was one of the most abundant Acalephs in the tow, 
and was taken at almost every station. The only distinction between it and 
the Pacific variety is that all our specimens were colorless, instead of having the 
polypites and nematocyst batteries yellowish or pinkish. 
Physalia megalista Péron rv LesueEvrR. 
Physalia megalista Péron, F., et Lesueur, C. A., 1807, Voyage aux terres Aus- 
trales, Mollusques et Zoophytes, plate 29, fig. 1. 
Physalia megalista Haeckel, E., 1888, ‘‘ Challenger ” Report, Zo6l., vol. 28. 
One specimen of Physalia belonging to this species was taken on January 19, 
off Tiladummati atoll. The pneumatocyst measured twenty-five mm. in 
length and was deep Prussian blue in color. 
III. CTENOPHORAE. 
Bolina ovalis, sp. nov. 
Plate 8, Fig. 28. 
This species appears closely allied to Bolina microptera A. Agassiz (N. 
Amer. Acalephs, 1865), and may prove to be identical with it. But the 
