The general collection of invertebrata extends round three sides of both galleries: from protozoa to brachiopoda in the upper; mollusca and tunicata in the lower gallery. The New Zealand invertebrates are placed in a single row of desk-cases, extending along the west wall of the lower gallery. The fishes, amphibia, and reptiles occupy the wall-cases in the lower gallery; a few of the smaller specimens (fossils, &c.) of the same groups are placed in desk-cases, and a considerable number of spirit specimens on a shelf, extending round three sides of the gallery, above the cases containing the mollusca. Lastly, as mentioned above, the birds occupy the wall-cases of the upper gallery, and the mammals those of the ground floor. Some of the larger specimens of the latter group are placed, not in cases, but in railed-off enclosures, in the centre of the ground floor; and the skeletons of moas and other large struthious birds are, on account of their great size, similarly disposed. In the case of vertebrata, as in that of invertebrata, the New Zealand specimens are kept separate from the general collection.

It is obvious that what is wanted, if the Museum is to be in any way an educational institution, is some contrivance for showing the relations of the various groups of animals to one another, and the place in the Museum where the representatives of each group are to be found. If this is done, the intelligent visitor, who, without time or inclination for exact scientific study, yet wishes to get some notions of natural history, will be guided in his search; and with the aid of a good popular work, such as Miss Buckley's "Life and Her Children," and" Winners in Life's Race," or Cassell's "Natural History," be enabled to acquire a fairly clear and accurate, although naturally superficial, knowledge of the form and general structure of animals, and of their relation to one another.

In the new Natural History Museum at South Kensington, this is done by setting apart the great central hall for an "Index-Collection," in which are exhibited types of the various groups of minerals, plants, and animals. But as the whole of our local museum would go into the hall in question, it is plain that we must be content with something on smaller scale.

a very much

To confine ourselves to the zoological collections, which take up by far the greater part of the Museum, it would seem that what we want is a collection in which each of the main groups of animals is represented by one or more examples, and in which these are arranged in such a way as to bring forcibly before the observer the mutual relations of the groups which they typify.

Since the theory of Organic Evolution has been recognized as the central doctrine of Biology, all classification of living things has been founded on the idea of genetic relationship.

From this it seems to follow that the best way to arrange a small index-collection of the kind mentioned in the preceding paragraph, is in the form of a solid phylogenetic diagram or genealogical tree."*

The model now exhibited is an attempt to carry out the principles just laid down. In it the main line of descent from protozoa to the higher vertebrata is represented by a vertical rod of wood three feet high, about 14 inches in diameter at its lower end, tapering somewhat towards its upper end, and firmly fixed below into a flat stand about one foot square. The various groups which do not lie on this main line are represented by side branches, which have usually an upward direction, but are inclined downwards from their point of origin in the case of degenerate types. Actual specimens, or, when these are unattainable, models of one or more examples of each group are placed in appropriate positions on the stem and branches, and labels are attached, giving (a) the name of the group, (b) the name of the representative specimen or specimens, and (e) the place in the Museum where the collection of specimens of the group is to be found.

I need hardly say that in the present condition of our knowledge of zoology, the subjective element enters very largely into the construction of a model such as this, and that the progress of research is certain to make alterations in detail necessary. I hope, however, that I have succeeded in representing with some degree of accuracy the mutual relations of the various animal groups.

Near the bottom of the stem is placed a model of an Amœba (A. radiosa), representing the myxopodous or pseudopod-bearing section of the protozoa, and a little higher up a model of one of the collared monads, Monosiga gracilis) representing the mastigopodous or cilium-bearing section of the same group. Close to the monad arises an ascending side-branch, bearing on its extremity a specimen of one of the New Zealand fibrous sponges (Chalinula sp.) as an example of the Porifera.

A short distance above the Amoeba and the monad, on the main stem, the group of Colenterata is supposed to begin, and is represented by models of a jelly-fish (Chrysaora cyclonota), and of a sea-anemone (Stomphia churchia), the former being_suspended by a wire, the latter placed on a small bracket. From this part of the stem a branch arises, representing the echinoderm phylum, and bearing a specimen of a star-fish (Asterias forbesii).

Still higher up the main stem the Type or Sub-kingdom Vermes

*My friend Professor Haddon, of the Royal College of Science, Dublin, has devised a most ingenious form of "diagram in three dimensions," excellent for lecture purposes, but less suitable in many ways for permanent exhibition in a museum than the one I propose.

begins; the lower or flat-worms being represented by a model of a planarian (Stylochus sp.), the higher or articulated worms by a specimen of a New Zealand Nereis, prepared by Semper's dry method. The Nereis is placed as if crawling on to a long sidebranch representing the arthropod phylum, and bearing specimens of the New Zealand fresh-water cray-fish (Paranephrops setosus), and the red-admiral butterfly (Pyrameis gonerilla).

Somewhat below the origin of the arthropod branch, and from the opposite side of the stem, springs a branch representing the group of Mollusca, and bearing an oyster (Ostræa edulis), and a model of the cellar-slug (Limax flavus). Close to the origin of this, two short and slender branches arise from the main stem, one bearing a brachiopod (Terebratella vitrina), the other a polyzoon (Retepora cellulosa).

A few inches above the worms, the vertebrate (or chordate) phylum is supposed to commence. Two descending branches, arising near together, represent the degenerate groups of the Tunicata (Urochorda) and Acrania (Cephalochorda): on the Tunicata branch is placed a model of a simple ascidian (Microcosmia pyriformis); from the end of the neighbouring branch is suspended a model of the lancelet (Amphioxus).

A short distance higher up the stem is another descending branch, on which is fixed a stuffed specimen of one of the New Zealand fresh-water lampreys (Geotria chilensis), representing the probably degenerate group Cyclostomata. Above this begins the lowest group of gnathostomatous vertebrata, the class Pisces, represented by a small specimen of the common New Zealand dog-fish or smooth hound (Mustelus antarcticus) suspended from the main stem. Still higher, also suspended from the main stem, is a specimen of the axolotl (Amblystoma tigrinum) as an example of the Amphibia.

A little above the place of attachment of the axolotl, the vertical stem comes to an end as such, dividing into two opposite branches of unequal length, the shorter representing the Sauropsida, the longer the Mammalia. On the proximal end of the shorter branch, representing the Reptilia, a specimen of the New Zealand spotted lizard (Mocoa grandis) is placed, close to the fork, and with its tail winding round the upper end of the main stem. On the distal extremity of the shorter branch is perched a New Zealand parrakeet (Platycercus novæ-zealandiæ) as a representative of Birds, while in a corresponding position on the longer branch is a marmoset (Hapale jacchus) as an example of Mammalia.

The labelling is an important feature of the model. For each group-type, or class, as the case may be-a label is provided giving the scientific and English names of the group, and of the species chosen to illustrate it, and indicating the place in the Museum where further examples of the group are to be

found. Two examples will illustrate the method of labelling adopted :

Type ARTHROPODA,

Including Crayfishes, Crabs, Centipedes, Spiders, Insects, &c.

Examples:

1. The Fresh-water Crayfish (Paranephrops setosus).

2. The Red Admiral Butterfly (Pyrameis gonerilla).

General Collection.-Upper Gallery, N. and S. sides, Desk Cases 18-38; Spirit Specimens on shelf above cases.

N.Z. Collection.-Lower Gallery, W. side, Desk Cases 5-11; Spirit Specimens on shelf above cases.

Class AVES (Birds).
Example:

Red-fronted Parrakeet (Platycercus nova-zealandiæ).

General Collection.-Upper Gallery, Wall Cases on E., W., and S. sides; Skeletons of Ostrich, &c., on ground floor, South enclosure.

N.Z. Collection.-Upper Gallery, Wall Case on N. side.

Moa Remains.-Ground Floor, S. enclosure; Upper Gallery, Desk Cases 41-43, and small wall case at S. end.

I am aware that several objections may be made to the construction of this model. From the strictly scientific point of view, undue prominence is given to the vertebrata, while many interesting invertebrate groups are omitted altogether. But this is done purposely the vertebrata must of necessity occupy a far larger share of museum space, and attract more attention, than invertebrates; so that it is, I think, advisable to call special attention to the classes of vertebrates, while the invertebrata may well be considered by sub-kingdoms or types. Again, the retention of the type Vermes is a sacrifice of strict accuracy to convenience; but the curator of a small colonial museum may be pardoned for sinning, in this matter, in company with Professor Claus, in whose text-book (English Edition, vol. i., p. 303) the same conventional union of the various and divergent worm-classes is made.

It is also incorrect to place any existing species, or indeed any existing lesser group, on the direct line of descent of the higher animals. For instance, it is tolerably certain that none of the ancestors of existing birds and mammals would, if discovered, be classifiable with any of the existing subdivisions, either of fishes or of amphibia; but it is none the less certain that what may fairly be called piscine and amphibian stages must have been passed through.

As a final objection, it may be said that a more correct mode of construction for a model of this kind would be to make the branches of such a length as to bring the ends of all of them, and consequently the specimens they support, to one level: advance of organization would then be indicated, not by height above the ground, but by distance from a centre, and all but the

distal ends of the branches would represent extinct forms. But such a model would be far less convenient than the one I have adopted.

In spite of these and other obvious objections in detail, I think the model may be considered as showing, fairly accurately, the main facts of zoological classification. For instance, it illustrates the impossibility of making a linear classification of animals: it shows the futility of discussing whether molluscs. are "higher" or "lower" than arthropods, both being shown to have arisen from comparatively low worm ancestors, and to have reached a high level of organization along totally different. lines it shows how, by degeneration, Amphioxus, although a vertebrate, has sunk below the level of organization of many invertebrates, and is as much below an ordinary fish as a fish is below a man: it further illustrates the now established fact, that while the two lowest groups of gnathostomatous vertebrates fishes, and amphibialie, speaking generally, in a linear series, the higher groups diverge in two opposite directions, birds springing undoubtedly from reptiles, mammals either from archaic reptiles or from some unknown group intermediate between reptiles and amphibia.

One advantage of the model I must not fail to mention its construction is simple enough to allow of comparatively easy alteration in the place of origin or direction of the branches, whenever the progress of zoology necessitates a change in our view of the relations of any group.

ART. X.-Notes on a Skeleton of Notornis, recently acquired by the Otago University Museum.

By T. JEFFERY PARKER, B.Sc., C.M.Z.S.

[Read before the Otago Institute, 11th August, 1885.]

SOME months since I was informed by Mr. Edward Melland that the skeleton of a Takahe had been found on his station, near Lake Te Anau, by Mr. Richard Henry, who, having a strong taste for natural history, had recognised the bones and carefully collected them.

The specimens were forwarded to Dunedin, and Mr. Melland was good enough to bring them to the Museum for my inspection. As the more important bones were present, and in very good preservation, I was glad to be able to purchase them, and thus to make a very important addition to the collection of native birds.

As is well known, the only recent remains of Notornis hitherto obtained are the two stuffed specimens in the British