tentacula; on its superior surface is a crest which remains above water,
and the wind blowing against it turns the animal round; they thus swim
with a rotatory motion; the crest is placed obliquely to the length of
the oval cartilage, and this position of it perhaps assists in producing
the motion; the crest is perfectly transparent, but marked with little
striae; the oval cartilage is marked with concentric striae, which
indicate the lines of its growth; in some this cartilage is transparent,
in others quite blue.

November 12. South latitude 30 degrees 11; east longitude 100 degrees 31
minutes 30 seconds.

We caught several beautiful animals this day, of the Medusae kind
(Diphya). (See Illustration 3 Diphya, Sp.)

Figure 1 represents a section through one of them, the size of life: the
bag (1) is of a delicate bright amber colour. The long tentacula issuing
out are upwards of a foot in length and of a bright flesh colour.

(Illustration 3)

Figure 2 is a section across the animal.

Figure 3 represents the mouth of the large opening at c, d, as if one was
looking down into it.

Figure 4 upper part; Figure 5 lower; and Figure 6 the perfect animal.

Between c d apparently lay the entrance to its mouth; in the little bag
marked (3) its long tentacula were concealed, and below these lay a