Many of the medusae and small gelatinous animals must be endowed with very acute sensibilities and perceptions, for they evinced extreme timidity if any substance approached them, and when plunged alive into spirits, their rapid movements and violent contortions repeatedly indicated acute pain; indeed so clearly that on this point there could be no mistake. A mass of gelatinous animals, caught this day, gave out a slight electric shock. Some of them were shaped like the portions of an orange, and they evidently were formed to fit into one another in the manner in which they were found, although they separated directly they were touched. July 2. South latitude 35 degrees 58 minutes; east longitude 17 degrees 54 minutes. This day the ship went so fast that we could not catch anything. The acalephae were not so numerous as they had been further to the north, but we saw more and larger medusae than I had ever before remarked. It indeed appeared as if the acalephae diminished and the medusae increased in number after passing the 36th degree of south latitude. July 12. ) South latitude 23 degrees 2 minutes; east longitude 0 degrees 26 minutes 45 seconds. July 13. ) South latitude 21 degrees 55 minutes; west longitude 0 degrees 44 minutes. The vessel went slowly through the water, but although the net was kept towing we could catch nothing, and there was no appearance of anything being in the sea. July 14. South latitude 20 degrees 52 minutes; west longitude 1 degree 49 minutes. This day we caught a Velella of the following dimensions: Length of interior cartilage 1.1 inches. Breadth of interior cartilage 0.5 inches. Total length of blue base 1.7 inches. Breadth of blue base 1.0 inches. Height of centre of crest 0.5 inches. Rim round crest, in breadth 0.55 inches. This animal differed from those caught on the 11th November 1837, in the following particulars: It was much larger. The base of the animal consisted of two parts. The centre portion was an elliptically-formed cartilage, elevated in the centre, and marked with eighteen concentric striae, which became thinner and thinner as they approached the centre. No striae were visible on the elevated crest with which the animal swims, but this crest was furnished or fringed with a thin moveable flap, 0.55 inches in breadth, which ran quite round it. The animal has the power of flapping this to and fro constantly, as a fish does its tail. The outer portion of the base was of a pale prussian blue colour, increasing in depth of shade both to the outer and inner edges. Many minute black spots were dotted all over this. The underside of the outer base was of a very dark prussian blue colour, and its lower interior edge was furnished with rows of blue tentaculae, which the animal uses as an elephant does its trunk. The whole interior surface of the oval cartilage is furnished with successive rows of white tentaculae, and in the centre is a long thin white tube, apparently its mouth.