animal, by the help of which they swim with some degree of activity when separated from each other. Several sorts are most generally seen joined together, gemmæ more particularly, which adhere in irregularly-shaped clusters of some hundreds; in the midst of these were generally found a few specimens of cornuta, from which circumstance we may judge that they are very nearly allied. It seems singular that no naturalist should have taken notice of these animals, as they abound so much where the ship now is, not twenty leagues from the coast of Spain. From hence, however, great hopes may be formed that the inhabitants of the deep have been but little examined, and as Dr. Solander and myself will have probably greater opportunity in the course of this voyage than any one before us, it is a very encouraging circumstance that so large a field of natural history has remained almost untrod until now, and that we may be able from this circumstance alone (almost unthought of when we embarked in the undertaking) to add considerable lights to the science which we so eagerly pursue.
This evening a large quantity of Carcinium opalinum, which may be called the opal insect, came under the ship's stern, making the very sea appear of uncommon beauty, their colours appearing with vast brightness even at the depth of two or three fathoms, though they are not more than three lines long and one broad.
7th. On examining the Dagysæ which were taken yesterday several small animals were found lodged in the hollow parts of their bodies, and some in the very substance of their flesh, which seems to be their food, as many of the Dagysæ were full of scars, which had undoubtedly been the lodgment of these animals some time before. Upon a minute inspection they proved to be animals not to be classed under Linnæus's genera, though nearly related to Oniscus, from which circumstance the name of Onidium was given to the new genus, and to them was added an animal taken on the 28th of August, and mentioned by the name of Oniscus macrophthalmus.
In one particular these insects differ from any hitherto
