It belongs to the third phyletic group, and all the ocelli appear at a very early stage.
Ocelli wanting; antennae more or less hidden in a groove.
Ocelli none; wings and hemelytra always present in the adults; no discoidal areole in the corium near the apex of the clavus.
Antennae inserted in the lateral or dorso-lateral margins of the head; antenniferous tubercles slightly projecting from the sides of the head; head produced strongly cephalad; ocelli at least as far apart as the eyes.
Ocelli not farther cephalad than the caudal margins of the eyes; segment two of the antenna single.
Disc of pronotum unarmed; apex of scutellum produced into a spine; ocelli close to the eyes; eyes large and close together.
Ocelli cephalad of the hind margins of the eyes; first segment of the antennae stout, second segment divided into many smaller segments.
First two antennal segments very short, last two long, pilose, third thickened at the base; ocelli present, veins of the hemelytra forming cells.
Antennae longer than the head; or if shorter, then the eyes and ocelli absent.
Ocelli present, if rarely absent in the female, then the tarsus has two segments; or if with three tarsal segments, the wing membrane with one or two cells.
Third segment of the antenna with five divisions; ocelli present.
By this it must not be understood that the ocelli of the Chærocampa larvæ invariably possess only this, and no other significance for the life of the insect.
If it be admitted that the ocelli of caterpillars are thus means of exciting terror, the difficulty of their occurring in protectively coloured species at once vanishes.
The brown variety has the subdorsal line on the three front segments only, distinct ocelli on the fourth and fifth segments, and gradually diminishing rudiments on the remaining segments.
Elpenor and Porcellus) the oblique stripes disappear when the ocelli reach complete development, and we may therefore venture to conclude that in these cases the former appeared earlier in the phylogeny.
Ocelli constitute a character which occurs in nearly all the species of the group--they are the goal towards which the phyletic force is urging, and which must sooner or later be reached by each member of the group.
Lastly, the several ocelli are separated from each other by a pale surface bearing irregular black marks.
Now in this species the two central tail-feathers alone are ornamented, each with two brightly-coloured ocelli, the ocelli having completely disappeared from the inner sides of all the other tail-feathers.
I should add that in the secondary wing-feather farthest from the body all the ocelli are smaller and less perfect than on the other feathers, with the upper parts of the external black rings deficient, as in the case just mentioned.
Hence I was led carefully to examine the tail-feathers of the several species of Polyplectron in order to discover whether the ocelli in any of them shewed any tendency to disappear, and, to my great satisfaction, I was successful.
African butterfly (Cyllo Leda) belonging to the same family, the ocelli are even still more variable.
The females of the several species of Polyplectron exhibit in a dim condition, and chiefly on the tail, the splendid ocelli of their males.
Formation and variability of theOcelli or eye-like Spots on the Plumage of Birds.
In this respect they differ remarkably from the tail-feathers of Polyplectron, which in most of the species are ornamented with larger ocelli than those on the tail-coverts.
Napoleonis the ocelli are confined to the tail, and the back is of a rich metallic blue, in which respects this species approaches the Java peacock.
These confluent ocelli differ from the single ocelli of the peacock in having an indentation at both ends, instead of at the lower or basal end alone.
The larger spots occupy exactly the same relative position on this feather as those occupied by the perfect ocelli on the longer wing-feathers.
The white dots that normally do duty as ocelliare not infrequently set in reddish-brown spots, and then become rather more noticable (Fig.
The ocelli of the Trinucleidae and Eoharpes are smaller, and the detailed structure not yet investigated.
In the adult, both the eye-lines and the ocelli are entirely wanting.
The stemmata are present only in Harpes, where there may be on the summit of the cheek two or three ocelli lying near one another.
The eyes of copepods are of interest, in that they suggest the paired ocelli of the Harpedidae and Trinucleidae.
The interest lies in the fact that while the ocelli and eye-lines were lost in development, the genal caeca are present in the adult, showing that they are different structures.
In some forms the dorsal ocelli are doubled, so that five in all are present (cf.
The relation of the genal caeca to the ocelli on the cheeks is best shown in the Trinucleidae.
In some half-grown specimens, traces of the ocelli can be seen, but the eye-lines are absent.
The similarity in position of the paired ocelli of trilobites and the simple eyes of copepods has perhaps a significance.
The Agarions are distinguishable from the Libellula and the Aeshna by their remarkably thin, filiform, and exceedingly elongated abdomen, and by the three ocelli arranged triangle-wise on the top of the head.
You would not be apt to notice these little ocelli on the grasshopper's head, they are so small, and besides, some of the grasshoppers do not have them.
Yes, John, the time may come when the ocelli will disappear from the insects.
Others think the ocelli are only capable of distinguishing light from darkness.
If you look full in the face of a cicada, you can see the three little roundocelli between the compound eyes.
Defn: One of the transparent lenslike cells in the ocelli of certain arthropods.
Their colors are commonly brown and gray, often with ocelli on the wings.
Sometimes the young are colored differently from the adult, having sky-blue spots and often ocelli on the fins, which disappear with age.
There is almost always a black bar across the eye, and often black ocelli adorn the fins.
These confluent ocelli differ from the single ocelliof the peacock in having an indentation at both ends, instead of only at the lower or basal end.
The explanation, however, of this difference is not difficult; in some species of Polyplectron the two oval ocelli on the same feather stand parallel to each other; in other species (as in P.
In this attitude the ocelli over the whole body are exposed at the same time before the eyes of the admiring female in one grand bespangled expanse.
The successive steps in the shading of the ball-and-socket ocellican be followed out with equal clearness.
The larger basal spots occupy exactly the same relative position on these feathers as do the perfect ocelli on the longer wing-feathers.
The ocelli are absent in the females of certain insects, as in the Mutillidae; and here the females are likewise wingless.
When I looked at the specimen in the British Museum, which is mounted with the wings expanded and trailing downwards, I was however greatly disappointed, for the ocelli appeared flat, or even concave.
In order to discover how the ocelli have been developed, we cannot look to a long line of progenitors, nor to many closely-allied forms, for such do not now exist.
Part of a tail-covert of Polyplectron chinquis, with the two ocelli of natural size.
Gonosome with free medusae or gonophores; the medusae typically with otocysts, sometimes with cordyli or ocelli (figs.
Ocelli are seen at the base of the tentacles, and also (as an exception) groups of medusiform buds.
In other cases ocellimay occur between tentacles, as in Tiaropsis (fig.
Eyes are either preserved or lost; when preserved they are represented either by a single one-lensed ocellus or by an aggregation of such ocelli on each side of the head.
The antennae are many-jointed, and there is a single ocellus or a cluster of ocelli on each side of the head.
Even the celebrated case of the Argus Pheasant shows that the bands from which the ocelli are developed arose from spots.
The analogy betweenocelli and concretions may be a real one.
In some larvae, those of the Sphingidae especially, ocelli occur, and these may be actually watched as they grow from dots to perfect eye-spots, with the maturity of the larva.
A study of ocelli naturally suggests such a process, which is analogous to the banding of agates, and all concentric nodules.
His careful analysis of the ocelli or eye-spots in the Argus pheasant and peacock have led him to conclude that they are peculiar modifications of the bars of colour as shown by his drawings.
At any rate beautifulocelli of all sizes can be seen forming in many iron-stained sand-stones.
In the words we have put in italics Darwin seems to admit these ocelli to be formed from blotches; and we think those of the Argus pheasant can be equally shown to arise from spots.
The growth of ocelli may thus be a mechanical process adapted by the creature for decorative purposes, but the artistic colouring of many eye-spots implies greater effort.
The transverse subapical band is pale yellow, almost white; the ocelli of the wings are more as in lavinia than in coenia.
The form with obsolescentocelli has been named silvestris by Edwards.
In the female the ocelli near the anal angle of the secondaries are usually well developed.
The primaries are marked with gray at the apex and on the outer margin, and have a submarginal and submedian transverse ferruginous line, between which the ocelli are located.
The eye-spots of the upper side reappear below, and in addition there is another near the outer angle of the secondaries, and a few silvery well-defined ocelli between the two on the secondaries.
All the specimens of tyndarus in my collection, and there are many, lack the ocelli on the fore wing, or they are very feebly indicated on the under side.
Easily distinguished from other species in our fauna by the presence of two more or less perfectly developed ocelli on the upper side of the fore wing and also of the hind wing.
The ocelli in both sexes are very well developed on both sides of the wings.
The number of the ocelli is not constant, and occasionally specimens occur in which they are almost wanting.
These ocelli are frequently arranged in series on each side.
The female does not differ from the male, except that the ocelli on the fore wings are larger and more conspicuous.
Distinguished from its allies by the total absence of ocelli on both wings, above and below.
This is another form, dark on the upper side and reddish below, in which the ocelli on the under side show a tendency to become obsolete, and in some specimens are wholly wanting.
Males with facetted eyes and no ocelli Monophlebidæ.
Smith has observed, the larger workers have simple eyes (ocelli), which though small can be plainly distinguished, whereas the smaller workers have their ocelli rudimentary.
There has been a good deal of discussion as to the relative functions of the ocelli and the facetted eyes of insects.
Remember its compound eye with mosaic vision, coarser by far than our retinal vision, and its ocelli of problematical value, and the complete absence of muscular adjustment in either the one or the other.
The view generally held is that the ocelli are specially useful in dark places and for near vision; while the facetted eyes are for more distant sight and for the ascertainment of space-relations.
The simple retinal eyes of gasteropods, and perhaps in some cases the ocelli of insects, probably belong to this class.
Passing now to the crustacea, we find in them eyes of the same type as in insects; but in the higher crustacea ocelli are absent.
In Mr. Wallace's book the meaning of the ocelli comes in by the way, in the explanation of Plate IX.
The ocelli on the wing feathers were favourite objects of Mr. Darwin, and sometimes formed the subject of the little lectures which on rare occasions he would give to a visitor interested in Natural History.
Where compound eyes are found, the ocelli never exceed three in number, and are arranged in the form of a triangle, and placed in the middle of the head (figs.
In Wallace's book, the meaning of the ocelli comes in by the way, in the explanation of Plate IX.
The ocelli on the wing feathers were favourite objects of Darwin's, and sometimes formed the subject of the little lectures which on rare occasions he would give to a visitor interested in Natural History.
D c) characteristic of this mutation: the wings are held out at a wide angle from the body, the ocelli are very much reduced in size or entirely absent, the bristles around the ocelli are usually small.
Carapace having evidence of more than one dark marginal line, and scattered, black spots or ocelli spinifer asper, p.
Blackish spots and ocelli vary in size and there are many kinds of pattern on the carapace.
Size of theocelli increases from west to east in populations of T.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "ocelli" in a variety of sentences. We hope that you will now be able to make sentences using this word.
