The only exception to this is presented by Scutigera, where the terga corresponding to the somites bearing the fifteen pairs of legs are reduced by fusion and suppression to seven.
These lie between theterga and sterna, and defend the spiracle.
The position of the terga and sterna after an inspiration, is indicated by the thick line; the dotted line shows their position after an expiration, and the arrow marks the direction of the expiratory movement.
A pair of limbs may next be inserted between the terga and sterna, and the simple segment thus composed occurs so extensively in the less modified regions and in early stages that it may well be considered the typical Arthropod somite.
The terga and sterna approach and recede alternately, the sterna being almost always the more mobile.
In the male Cockroach ten abdominal terga are visible without dissection (fig.
The eight abdominal spiracles belong to the first eight somites; each lies in the fore part of its segment, and hence, apparently, in the interspace between two terga and two sterna.
Professor Huxley has unfortunately disturbed the consistent use of this term by giving the name pleura to the free edges of the terga in Crustacea.
The terga and sterna approach and recede alternately, while the pleural zone simultaneously becomes depressed or returns to its original figure.
The two succeeding terga are of nearly equal size, and each is much shorter than the pronotum, contrary to the rule in winged Insects.
Terga 8 and 9 not externally | Terga 8 and 9 externally visible.
While the thoracic terga diminish backwards, the sterna increase in extent and firmness, proportionally to the size of the attached legs.
The testes may be found in older larvæ or adults beneath the fifth and sixth terga of the abdomen.
Fused terga of the prosoma followed by the opisthosoma of four visible somites.
The soft integument and limbs of the mesosoma have been removed as well as all the viscera and muscles, so that the inner surface of the terga of these somites with their entopophyses are seen.
Opisthosoma without trace of separate terga and sterna, the segmentation merely represented posteriorly by slight integumental folds and the sterna of the 1st and 2nd somites by the opercular plates of the pulmonary sacs.
They are attached longitudinally to the two crests, including and formed by the muscles running from the terga to near the basis of the shell.
The terga vary considerably in shape, according as the basi-carinal corner is more or less truncated.
The shape of the terga is variable in nearly all the species, and greatly so in T.
This articulation of the scuta and tergais prefigured amongst the Lepadidae, in Pollicipes mitella, and in Lithotrya.
Terga: in three sets of specimens the terga differed considerably, but as in every other respect there was the closest resemblance, I do not doubt that these are merely varieties.
Kingii the terga and scuta are firmly calcified together.
I have formerly remarked that the shape of the terga seems influenced by the size of the orifice.
On each side of the orifice, there is a pair of calcareous beads, representing the two scuta and two terga of ordinary Cirripedes; and between the scuta a minute black eye is generally conspicuous.
On the upper side of the abdomen the terga of the somites overlap, the front part of each being pushed under the tergum in front when the abdomen is straightened, and only exposed to view when the abdomen is bent.
The carapace which covers the upper side of the head and thorax is not formed, as might be thought, simply by the terga of the somites becoming soldered together.
The horny substance of both scuta and terga is uniformly yellow; though in dryed specimens, from the underlying corium being seen through the valves, these generally have a tinge of blue.
The capitulum is not much compressed, a horizontal section giving an oval figure; it is placed obliquely on the peduncle, the scuta descending lower than the terga and carina.
That margin in the scuta and terga which opens and shuts for the exsertion and retraction of the cirri, I have called the Occludent margin.
Leach Cineras chelonophilus, for in both, the top of the capitulum is bluntly pointed and the terga are solid within; in the Var.
Rhodiopus, the carinal angles of the terga are produced into points, and in L.
Valves 5; carina with a truncated and crested base; scuta with strong internal umbonal teeth; terga with the basal point truncated, almost parallel to the occludent margin.
Hence Lucan in their praise says of Caesar, "Territa quaesitis ostendit terga Britannis.
In Arachnida the highest forms exhibit a fusion of the tergites of five post-oral somites to form one continuous carapace united with the terga of the two prosthomeres.
Crustacea), including prosthomeres, all ankylosed by their terga to form a cephalic shield.
The wings of Hexapoda are lateral expansions of the terga of the second and third thoracic somites.
In Crustacea the fourth or mandibular somite never has less than the two following somites associated with it by the adaptation of their appendages as jaws, and the ankylosis of their terga with that of the prosthomeres.
In Diplopoda two opisthomeres--that is to say, one in addition to the buccal somite--are united by a fusion of their terga with the terga of the prosthomeres.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "terga" in a variety of sentences. We hope that you will now be able to make sentences using this word.
