||4. Calm today; we were employd in fishing with the casting net and were fortunate in taking several specimens of Dagysa saccata adhering together, sometimes to the Lengh of a yard or more, and shining in the water with very beautifull Colours; but another insect which we took today was possest of more beautiful Colouring than any thing in nature I have ever seen, hardly excepting gemms. He is of a new genus and calld [ ] of which we took another species who had no beauty to boast, but this which we called opalinum shone in the water with all the splendor and variety of colours that we observe in a real opal; he livd in the Glass of salt water in which he was put for examination several hours; darting about with great agility, and at every motion shewing an almost infinite variety of changeable colours. Towards the Evening of this day a new phaenomenon appeard, the sea was almost coverd with a small species of Crabbs Cancer depurator of Linnaeus, floating upon the surface of the water, and moving themselves with tolerable agility, as if the surface of the water and not the bottom was their Proper station. Here again as usual our casting net was of great service, we took with it as many as were wanted, and went to bed well contented with the Produce of the day.