barred with brightest gold, and found flying over short grass under furze-bushes.

E. chrysoclista, common in St. James's Park in June and July; remarkable for its metallic tufts on a deep orangecoloured wing, bordered with black, and with purplish-black under-wings. It has three tufts of black and silver scales on each wing.

(Fig. 11.) Ochsenheimeria is properly not a microscopic moth, for it is from five to six lines in expansion, and not particularly beautiful; but the head is most curious, and deserves observation (Fig. 15). Those feathered antennæ and bird-like eyes are unlike all other moths. We can only catch this little grey fellow in the hottest part of the day, from 12 A.M. to 2 P.M., when it hops about the grass, depositing eggs on the Dactylis glomerata. It is marvellously quick in hiding away, and if not swept into the net whilst on the wing, will not be easily secured.

(Figs. 12 and 14.) The Gelechidee have varied habits, for the larvæ of many of them feed between the united leaves of sallows, honeysuckle, firs, oaks, and apple trees. One species, G. mulinella, luxuriates in the sweet flowers of the broom and the furze in July and August. G. malvella (Fig. 12) is a plague to the florist who may especially care for his hollyhocks, and grieve to find his seeds devoured by the larvæ of this moth ; but G. hermanella (Fig. 14) is a true leaf-miner. We find the larvæ making dirty green blotches on the leaves of Chenopodium and Atriplex, and the moth, flitting over these plants in July and October, is bright orange red, flaked with silvery streaks, and set off by jet-black scales. These moths are scarcely microscopic, being from six to nine lines in expansion.

(Fig. 13.) Cerastoma xylostella. Measures ten lines across the out-stretched wings, yet it belongs to the MicroLepidoptera, and its larva, bright green, with scarlet stripe along its back, will in July be feeding on the honeysuckle.

(Fig. 9.) Glyphipteryx equitella.-Not a leaf-miner, but a burrower, and with a truly microscopic beauty, for the exquisite markings of its wings are never well seen except with a pocket lens or a three-inch object-glass. The dark bronzy-grey ground is streaked with pure white, edged with silver; two violetsilvery spots in the middle, and another at the tip, near which a hook of jet-black scales project through the cilia. This moth flies over the stonecrop in June, where it deposits the eggs, from whence a little miner comes forth to plunge into the stem, and work away in a channel through which it revels in the ascending sap. Another extremely pretty species is the darkgreen Thrasonella, abundant amongst the rushes in June and July; and these are so varied that no two are exactly alike.

The wings of G. Thrasonella have streaks of bluish silver more or less distinct, and the large blotch of black lightened by three silvery violet eyes may not be found equally brilliant in all; even the cilia is sometimes more broadly tipped with white, and the bronzed green thereby relieved. The size also varies from three to six lines across.

Then, upon the pure white clustered blossoms of Anthriscus, or Wild-beaked Parsley, we frequently see a dark, small moth resting, and then running to and fro, raising and depressing its lovely wings as if fanning itself. This is G. Fischeriella. We know not where its larva feeds, nor is it confined to the Anthriscus, though it seems to love that flower best. We find it in the garden upon candytuft and other flowers; also swarming round young fir-shoots. Only with a microscope can we rightly see the tinted plumage of the dark velvetty wing, striped with white and silver, and having one rich violet eye in the anal corner.

I have but to notice the head of Coriscium (Fig. 16), an oak-leaf miner, plentiful in April, June, August, and September, whose drooping and tufted palpi show us the minute yet decided variations which mark the species, as well as the beautiful-plumed head of Ochsenheimeria.

Pondering on the hieroglyphics these little miners trace, words of infinite wisdom to the eye that can read and the heart that can understand; seeing how in darkness yet perfect security the naked worm feeds, grows, and developes a new and wondrous beauty of which it is wholly unconscious, and of which for thousands of years man was profoundly ignorant; we pause reverently before the tracery on a rose-leaf, the blotch on the laburnum, and we look beyond the present mystery of our own life, oftentimes a dark and a winding way, with a hope strengthened in looking at the glorious wings of the hitherto scarcely appreciated Microscopic Moth.

ON FOSSIL OTOLITHS,

AND NOTES ON THE

AUDITORY ORGANS OF THE LOWER ANIMALS.

BY W. W. STODDART, BRISTOL.

THE subject under consideration is one of the highest interest both to the geologist and comparative physiologist.

The fossil otoliths of fishes have generally escaped the notice of fossil collectors, which is the more strange, as the author has obtained some hundreds of specimens from some of the British strata. Nor are they described in any work yet published on geology. The nearest approach is in the first volume of the Geological Journal, where Professor Owen describes the petrotympanic bones of four species of fossil Balanidæ from the Suffolk crag.

It indeed appears that very little is said by any author on comparative physiology concerning the auditory organs of recent osseous fishes. This in some measure arises from the universal dissection of cartilaginous fishes, whose heads, being more transparent, are easier of manipulation.

A few years ago an esteemed friend of the author's, E. T. Higgins, Esq., well known in the geological world, while examining the marine sand from Hordwell Cliff, found some curious little fossils which had never been figured or described. A careful examination and comparison proved them to be really the "otoliths" or ear-bones of fishes.

In the February number of the Zoologist for 1859, Mr. Higgins published a short notice, stating the fact that he had found the ear-bones of many recent genera of fishes in a fossil state. Since that time both he and the author have been carefully examining all the geological strata for these remarkable little fossils. And so successful has been the investigation, that besides several new facts in the anatomy and natural history of fishes, the fossil otoliths of the cod, whiting, whiting pout, power cod, pollack, flying fish, and many of the Pleuronectida have been determined.

They have been principally found in the Crag of Suffolk, the Eocene beds of Sussex, Hampshire, and Isle of Wight.

In a very remarkable bed in the Bristol Lias, the author has collected a body that very probably may turn out to be an otolith of the Pholidophorus; but as only one specimen has yet been found, its nature cannot yet be determined with perfect confidence.

In order to ascertain the species of fish to which the several

ear-bones belong, it is necessary to dissect an immense number of heads; for a most striking fact has been demonstrated, and one without analogy in natural history, viz., that a characteristic form is more peculiar to the species than the genus or family. That is to say, the ear-bones of a species have invariably a configuration peculiar to itself. But no form has yet been observed that will point out a genus, family, or tribe; for example, the same general form is equally found in the ear-bones of the Clupeida and Scombridæ, but still there is no difficulty in determining, with the greatest confidence, the specific name of a mackerel or a herring by the markings on their ear-bones, because they are always constant and never the same in two species.

With all these interesting relations and the frequency of their occurrence, it is very remarkable that the fossil otoliths have not been noticed before. The collection of Mr. Higgins and the author contain more than forty species of fossil otoliths, all distinct, and many of fish hitherto unknown in the fossil state.

Otoliths occur much more abundantly in the tertiary beds than any other parts of fishes, and much more so than the teeth. This fact at first sight may appear startling to the collector from the paleozoic rocks, when the commonest remains are the teeth, spinous defences, and scales. But a little reflection will easily solve the apparent riddle.

In the Silurian, carboniferous, etc., seas, the principal inhabitants were cartilaginous fishes, and the hardest and most indestructible portions of their bodies were the teeth and spines; whereas in the later tertiary beds the osseous fishes predominated, which do not possess the fin-spines or solid crushing teeth. Of them the hardest parts are the ear-bones in question.

That they are really the otoliths of osseous fishes their figure and configuration undoubtedly prove; but the more clearly to explain the position and function of an otolith, it will be better to trace the development of the auditory organ from the lowest organism in which the author has noticed it, to the complete and elaborate ear of the mammifer.

Sound is the vibration of solids and fluids propagated by means of waves through some intervening medium. At least such is the present theory.

Now the office of an ear is to intercept and collect these undulations, and to convey the result to the brain of the individual.

In every auditory organ there are two things absolutely necessary, viz.:

1st. A fluid wholly or partially filling the internal ear.

2nd. A solid body or bodies of greater specific gravity than

the surrounding substance over which the auditory nerve is expanded.

On reviewing the different forms of ear, we find these conditions always present.

Of course animals that live in two media that have such different densities as air and water, require two distinct adaptations of auditory apparatus, although the same principles are present in each.

A sound that would be melodious and musical to the human car would be absolutely stunning to that of a fish, simply from water being a better conductor than air.

Abbé Nollet performed many experiments to prove this. While totally immersed in water, he struck together two pieces of stone or metal, when the resulting sound as perceived by the ear was quite unsupportable.

The simplest form of an ear is that found in aquatic animals. It is at the outset merely a cavity filled with fluid, over the surface of which a nerve is expanded. This only receives the vibrations in a very imperfect manner, and is quite incapable of resolving them into tones.

This simple arrangement is by no means the usual one; commonly the sac is enclosed and filled with a gelatinous fluid (endolymph), which, when the undulations were received, would, on account of its greater specific gravity, more clearly communicate the full force of the sound, through the nerve to the sensorium.

The next step to increase the hearing power is the addition of a solid to this gelatinous fluid, and which, according to wellknown acoustic laws, would materially increase the sensibility to vibratory influence.

A still greater advance is the suspension of the whole in a more liquid material (the perilymph).

Almost every seaside visitor will recollect an apparently lifeless mass of jelly that so frequently lies on the beach. Divide it with a knife, and it shows no sensibility. Cut it into a dozen pieces, and it offers no opposition. Lay it out to dry in the sun, and what before was so many pounds is now scarcely as many grains, only a mere film. The most acute observers have as yet failed to prove the presence of a nervous centre. Nevertheless this living wonder possesses ears! and those of a very beautiful construction.

On placing this seemingly inert mass in a little sea-water, it will unfold in the most elegant proportions, and is at once perceived to be the Rhizostoma pulmo, or sea-blubber. When a small piece of the edge of the umbrella is placed under the microscope with an inch lens, a small notch with a cavity will readily be seen. In the centre of this is a small body suspended