He pointed to a singularly perfect and beautiful trilobite which was lying on a pile of manuscripts.
One of the girls says she wears a trilobite for a breastpin; some horrid old stone, I believe that is, that was a bug ever so long ago.
So far as the appendages of Hymenocaris are known, they agree very well with those of the Nebaliidae, and since they are of the trilobite type, it may safely be stated that the Trilobita and Malacostraca are closely related.
It probably had no test, and it may be noted in this connection that Naraoia had a very thin shell, as shown by its state of preservation, and was in that respect intermediate between the trilobite and the theoretical ancestor.
The asaphid, for instance, has been thought of as descended from some trilobite with rich segmentation, and a body-form like that of a Mesonacis or Paradoxides.
This kind of trilobite probably represents the normal development of the group in Ordovician and later times.
The exopodites of the cephalon, as of the body of Neolenus, are very different from those of any other trilobite whose appendages were previously known.
Cryptolithus is the only trilobite which has furnished any actual evidence as to its food.
It has been a custom of long standing to compare the trilobite with Limulus.
Every analysis of the cephalon of the trilobite shows that it is made up of several segments, certainly five, probably six, possibly seven.
This has been done in the preceding pages and evidence adduced to show that the primitive features of a trilobite indicate a swimming animal, and that the adaptations are those which enabled it to assume a crawling mode of existence.
Wahlenberg was also the first to describe an hypostoma of a trilobite (p.
The median eye has not so far been seen in any young trilobite in any stage previous to that in which compound eyes are present.
Four stages in the development of the trilobite Agnostus nudus.
Five Stages in the development of the trilobite Sao hirsuta.
Trilobite so far as its segmentation and trilobation are concerned.
The orthoceras and trilobiteare found, but become extinct with this formation.
In others, as the Cephalaspis, the plate of bone on the back is so large as to cover nearly the whole body, and make it resemble a trilobite (Fig.
Trilobite forms are smaller, and their numbers decrease.
Beecher give an idea of the under surface of the trilobite such as has never been obtained before, and demonstrate how closely the condition of things found in Apus (Fig.
There is, undoubtedly, an appearance of finish at the termination of these skeletal fringes, as though they terminated in a definitely shaped spear-like point, just as is seen in the trilobite pleurae.
They cannot be called crustaceans or arachnids, for in all probability they gave origin to both; the nearest approach to the Trilobite stage of development at the present time is to be found perhaps in Branchipus (Fig.
This might be called the Chordate Trilobite stage (Fig.
The whole period may be spoken of as the great trilobite age, just as the Tertiary times form the mammalian age, the Mesozoic times the reptilian age, etc.
A) which I have deduced from the embryological evidence, might very well represent a cross-section of a trilobite, provided only that each appendage of the trilobite possessed an excretory coxal gland.
Among the forms of trilobite extremely characteristic of the Lower Silurian throughout Europe and North America, the Trinucleus may be mentioned.
Yet, notwithstanding the numerous species of preceding naturalists which he has thus succeeded in uniting into one, he announces a forthcoming work in which descriptions and figures of 250 species of Trilobite will be given.
On the fifth day James Trilobite Eton said we were now getting near the point where we would find what we sought.
James Trilobite Eton of Concord never moaned, never gigged back or shed a hot, remorseful tear in this powdery, hungry waste of gray, parched ruin.
Toward evening James Trilobite Eton gave a wild shriek of joy and ran to us from the bed of an old creek, where he had found an ichthyosaurus.
We scorned such game as that and trudged on, cheered by the hope that seemed to spring eternal in the breast of James Trilobite Eton of Concord.
The dominant form is the trilobite of the genus or group Olenellus, which contains a great variety of species referable to three or four divisions which have been ranked as separate genera by some writers.
One of the most marked cases of apparent recurrence known some years ago was the reappearance of a genus of trilobite Ampyx in Ludlow rocks, found in the Bala rocks, but not in the Llandovery or Wenlock strata.
The best-known example is the trilobite AEglina rediviva.
There is not a living Crab represented so fully in any of our scientific works as is that one species of Trilobite whose whole story Barrande has traced from the egg to its adult size.
The eye of the Trilobite tells us that the sun shone on the old beach where he lived; for there is nothing in Nature without a purpose, and when so complicated an organ was made to receive the light, there must have been light to enter it.
Daisy was more eager than he; she wanted very much to have a trilobite for her own keeping; the difficulty was, she did not know how to look for it.
The doctor at last let her into the secret that he had a trilobite too; and the next time he came he brought it with him.
Whereupon the lady drew herself up and remarked in the clipped accent of a parrot: "No, sir; it's a carboniferous trilobite of the Upper Silurian.
Three weeks after hatching an ecdysis takes place, and the larva passes from a trilobite into a limuloid form.
A later embryo at the Trilobite stage, from the dorsal side.
The Trilobite is an early and imperfect experiment of the class, and the larva of the modern king-crab bears witness that it has not perished without leaving descendants.
The Trilobite was the most arresting figure in the Cambrian sea, and its fortunes deserve a paragraph.
The doctor at last let her into the secret that he had a trilobite too; and the next time he came he brought it with him.
Let the trilobite alone, and let's have Grimm's Tales to-morrow shall we?
The Trilobite burrow is known as Ruschinites, and has been supposed to be a sea-weed of the kind called Bilobites.
Constructed as above described, the Trilobite could swim, as is supposed, usually on its back or side.
Both types meet us in the Early Cambrian, but while the Mollusk is there represented only by low forms, the Articulate is then not only in the humble guise of the worm, but in the complex and highly organised form of the Trilobite (Figs.
Burrows of Trilobiteand of modern King-crab 81 77.
Contemporaneously with the dawn of the Trilobite group, appear some small shrimp-like forms (Fig.
A Trilobite is a creature in whose structure the number three is dominant.
The upper surface of the body of a Trilobitewas defended by a strong shell or "crust," partly horny and partly calcareous in its composition.
A new genus of trilobitecalled Plutonia Sedgwickii, not yet figured and described, has been met with in the Harlech grits.
It was not till 1870 that Mr. Billings was enabled, by means of a specimen found in Canada, to prove that the trilobite was provided with eight legs.
The trilobite with the largest number of rings, Erinnys venulosa, occurs here in conjunction with Agnostus and Microdiscus, the genera with the smallest number.
The Homalonotus, a form ofTrilobite in which the tripartite division of the dorsal crust is almost lost (see Figure 544), is very characteristic of this division of the Silurian series.
For example, the two heads of the woolly rhinoceros in the slab engravings of the Trilobite grotto (Fig.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "trilobite" in a variety of sentences. We hope that you will now be able to make sentences using this word.
