Being a calm, I gave the men leave to bathe this afternoon, and was one of the first overboard myself. Within an hour and a half after we had done bathing, a cry of a shark was raised, and in truth there was the monster (the first we had seen). I mention this fact as tending to support what I have often heard stated, namely, that a shark's sense of smell is so keen that, if men ever bathe in seas where they are found, a shark is almost sure to appear directly afterwards. This really occurred in the present instance. We repeatedly caught many little animals which I believe are the VELELLA of Lamarck. They consist of a flat oval cartilage, on which they float; there is a mouth in the inferior surface of this surrounded with many 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 little gut marked (4) which communicated with the point (L) by a small canal: (1) was its swimming apparatus, and by alternate contractions and expansions of this, it took in and expelled water, and thus acquired a rapid motion, the pointed end (L) moving forwards. Its length was 1.7 inches. Breadth, 0.7 inches. Thickness, 0.35 inches. Temperature the same as the water, 65 degrees Fahrenheit.