REVIEW
OF
THE ZOOLOGICAL COLLECTION
OF
FR. ESCHSCHOLTZ,
PROFESSOR AT THE UNIVERSITY OF DORPAT.
It may easily be conceived, that in a sea-voyage a naturalist has fewer opportunities of enriching his collection, than when travelling by land; particularly if the vessel is obliged to pass hastily from one place to another, with a view to her arriving at her destination within a limited period. During our three years' voyage, little more than the third of our time was spent on shore. It is true, that curious animals are occasionally found in the open sea, and that a day may be pleasantly passed in examining them; but it is also true, that certain parts of the ocean appear, near the surface, to be almost wholly untenanted; and accordingly a passage of eleven weeks produced only ten species of animals: these, however, being met with only at sea, are still but partially known to the naturalist, and were the more interesting to me, as, during the preceding voyage, I had become acquainted with many remarkable productions of the ocean. My best plan will be, to arrange in a chronological order all the zoological observations which offered in the course of this voyage. The first, then, was the result of a contrary wind, by which we were detained much longer than we intended in the Baltic, and thus enabled to use our deep fishing-nets upon the great banks: these brought to light a considerable number of marine animals. Upon the branches of the spongia dichotoma, some of which were twelve inches in length, sat swarms of Ophiura fragilis, Asterias rubens, Inachus araneus, I. Phalangium, I. Scorpio, Galathea strigosa, and Caprella scolopendroides Lam. We obtained, at the same time, large pieces of Labularia digitata, Sertularia abietina, upon which nothing of the animal kind was to be seen, but attached to which was frequently found Flustra dentata; also Pagurus Bernhardus, Fusus antiquus, Rostellaria pes pelecani, Cardium echinatum, Ascidia Prunum, Balanus sulcatus, Echinus saxatilis, and Spatangus flavescens. Two different species of Actiniæ, seated on stones, were brought up, which were not to be found either in Pennant's British Zoology, or in the Fauna danica.
During a calm, by which we were detained two days on the Portuguese coast, Janthina fragilis and exigua, Rhizophysa filiformis, and another species, were brought up. Many specimens of the Janthina exigua were found, the bladder-like mass of which was stretched out to a great length, and bent into the form of a hook at the end. On the outer side was observed a fleshy streak, bordered by a close row of small paunches: these paunches, which were externally open, contained a great quantity of brown atoms, apparently spawn, and evidently in motion. With respect to the Rhizophysæ, it has been discovered that they are of the same genus as the Physsophora, the hard part being torn away in the act of catching them; upon this occasion also, several of these separated parts, still in motion, and bearing some resemblance to salpas, were brought up, and accurately examined.
Off the Cape de Verd Islands, in addition to the Exocœtus volitans, which abounds there, various specimens of the much larger Exocœtus exsiliens of Cuvier alighted on board our vessel. The latter species is distinguished by the long black fins of the belly, and by its remarkably large eyes, differing greatly from the species described by Gmelin under the same denomination.
The calms near the Equator afford an abundant harvest to the zoologist, the tranquil water presenting an immense variety of marine animals to his view, and allowing him to take them with little trouble in a net. The open woollen stuff used for flags offers the most convenient material for making these nets, as it allows the water to run through very quickly, and does not stick together. A short, wide bag should be made of this stuff, which may be stretched upon the hoop of a cask, and the whole fastened to a long, light pole. From the height on which we stand above the water, it is impossible to perceive the smaller animals; the best way therefore to catch these is, to hold the net half in the water, as if to skim off the bubbles of foam from the surface; then, after a few minutes, if the net is drawn out, and the interior rinsed in a glass of fresh sea-water, one may frequently have the pleasure of seeing little animals of strange forms swimming in the glass. In the course of ten days, I obtained, in this way, thirty-one different species of animals, among which was a small Diodon, eight small crustacea of forms almost wholly unknown; a sea-bug (Halobates micans); three species of Pteropodes, closely allied to the Cliodora; a small and remarkable Hyalœa; two new Janthinæ; Firola hyalina, Pyrosoma atlanticum, Salpa cœrulescens, and another unknown; Porpita glandifera, and a new species of globular form; a Velella; two new species of Acalephes, of the same family as the Diphyes; and further Pelagia panopyra, and two other very small species. When the sea was a little agitated on the Brazilian coast, we frequently saw the large sea-bladder floating on the surface; here we also caught with our net a new species of small Hyalœa, and of the fin-footed Steira, which approaches the nearest to the Limacina.
Brazil has lately been visited by eminent naturalists, who have spent years in the country, and have travelled through it in every direction; we are therefore bound to suppress the few detached observations we were able to make during the short space of four weeks.
Captain Von Kotzebue having frequently sent his people to fish in the Bay of Boto Fogo, we enriched our collection by thirty-two kinds of fish, the greater part of which were very similar to those already described as tenants of the Atlantic, but still differing from them in some respects.
How abundant the insects of Brazil are is generally known, particularly in the warm and moist lands along the coast, in the vicinity of Rio Janeiro. Few of them crawl on the ground; the greater part of them live on the leaves and fruits, or under the bark of trees, in flowers, and in the spongy excrescences of the trees. Among the coleoptera, the Stachylinus is a rarity: the white-winged Cicindela nivea of Kirby is to be found in great abundance on the sand of the beach, which is of the same colour as itself; the Cic. nodicornis and angusticollis Dej. on the other hand, frequent the paths in the forests. Cosnania, which supplies the place of our Elaphrus, is found among the grass by the side of brooks. The little animals of the Plochionus and Coptodera species climb, by means of their indented claws, along the moss on the trunks of the trees: their numbers, in these extensive forests, must be immense. Of the Cantharis, the number is small; the strongest of which is the Cantharis flavipes F. the descriptions of which vary, so that it may still be doubted whether we have a correct account of it. To show the proportion of the numerous subdivisions which we observed in the different genera, it will be sufficient to give the numbers of those which we were able to collect during the short period of our stay:—these were, Elater, 37; Lampyris, 17; Ateuchus, 14 (including the Deltachilum and Eurysternus); Passalus, 13; Anoplognathidæ, 14; Helops, (including Stenochia and Statira) 17; Curculionidæ, 108; Cerambycidæ, 101; Cassida, 24; Haltica, 26; Doryphora, 12; Colaspis, 15; and Erotylus, 12. The Phanæus, according to MacLeay, distinguished by the total absence of claws from the feet, is peculiar to the warmer parts of America: Onthophagus is not met with along the shore, but is found in the interior. Such large Copris as are seen in the old world, (Isidis, Hamadrias, Bucephalus,) have not been discovered here: their place is supplied by the large Phanæi, Faunus, bellicosus, lancifer, &c. A golden-green Copris is a great rarity. Onitis seems to be quite wanting in America: all the specimens, in this part of the world, that have been placed in that class, belong partly to the Phanæus, and partly to the Eurysternus Dalm. a remarkable species of the genus Ateuchus.
The Ateuchi are not less numerous in South America than in Africa; and here is found what may be looked upon as the intermediate link between Copris and Onitis. No part of the world is so rich in Rutelides as trophical America; and according to the narrow limits within which Mac Leay confines this family, it would seem to be exclusively restricted to this continent. The greater part have not the head divided from the head-shield by a line, and the breast is lengthened in front into a spine: this extensive division is peculiar to America. In the second division, the head-shield of which is bounded by a strongly marked line, those which are provided with a breast-bone are American. South America possesses also the intermediate genus between the Rutelides and Scarabæi, in the genus Cyclocephala, Anoplognathidæ were hitherto known to us from New Holland, Asia, South Africa, and South America, and are characterised by the drooping form of the upper-lip, falling lowest in the middle, and by the inequality of their claws; the under-lip, at the same time, has either a projection in the centre, or consists of two parts lapping over one another. In the same way that the Anoplognathidæ of New Holland have the appearance of Rutelides proper, are the South American Anoplognathidæ distinguished by their resemblance to Melolonthidæ: those of Brazil have no breast-bone, and at least one claw to each foot is cloven, which distinguishes them from those of Asia. Chelonarium and Atractocerus fly about in the evening, and are attracted by a light. The Brazilian jumping beetles differ, almost all of them, in their form, from those of Europe. Among the Heteromerides, in the neighbourhood of Rio Janeiro, owing to the dampness of the soil, no unwinged beetle is to be met with; a few varieties of the species Scotinus have been found upon the Organ mountains only.