There are also on the last segment a double and two single black chitinous plates.
Nevertheless the filament is a complete tube formed of chitinous substance and clothed externally by ciliated epithelium, internally by endothelium and lacunar tissue--a form of connective tissue--as shown in fig.
Siphons long, united, covered by a chitinous sheath, not completely retractile.
The chitinous substance ch is observed to be greatly thickened as compared with what it is in fig.
Its early characteristic was the acquisition of a chitinous coat over the body.
From the distal ends of the cells are secreted chitinous rhabdomeres, forming a rhabdom which occupies and fills up the central portion of the cup beneath the middle of the corneal lens.
The exoskeletal elements of a typical somite consist of a dorsal plate or tergum, a ventral plate or sternum, a lateral or pleural membrane, often strengthened with chitinous sclerites, and a pair of appendages.
In the Oigopsida the shell is represented by a proostracum which is no longer calcified by forms a chitinous plume or gladuius, and a similar rudiment occurs in Loliginidac (fig.
In the living genera, except Spirula, the shell is a chitinous gladius.
Lastly, in the Octopoda the shell is represented only by smallchitinous rudiments to which the retractor muscles of the head and funnel are attached; these are paired in Octopus, unpaired in other cases as in Cirrhoteuthis.
The gill bars separating the gill slits from one another are strengthened by chitinous rods in a way closely similar to that in Amphioxus.
These are a pair of chitinous rods which lie ventral to the notochord and in the collar region unite to form a single mass.
This consists of a series of chitinous elastic rods which strengthen the gill bars and are alternately forked and unforked ventrally.
On this distended receptacle appear several darker plates; these are the remains of the chitinous parts of the primitive wings.
The galea, or middle division, forms a simple lobe, while the lacinia has two large chitinous teeth on the inner edge, and internally four or five hairs arising from a thin edge.
Beetles are as a rule remarkable among insects for the firm consistency of their chitinous cuticle, the various pieces (sclerites) of which are fitted together with admirable precision.
The greater part of the digestive canal and the whole air-tube system are formed by inpushings of the outer skin (ectoderm) and are consequently lined with an extension of the chitinous cuticle which is shed and renewed at every moult.
The most profound metamorphosis is but a special type of growth, accompanied by successive castings and renewings of the chitinous cuticle, which envelopes all arthropods.
In place of the calcareous cuttlebone of the sepia the squids have their bodies stiffened by an internal strip of chitinous substance called the "pen.
The body is protected by chitinous plates above and below.
The head is connected with the thorax by a neck often protected by the overlapping front of the "tergum," or chitinous plate that covers the thorax.
Horn is a chitinous material developed from the skin, and not dissimilar to hair; indeed it would be no great stretch of facts to say that a cow's horn was composed of agglutinated hairs.
The body cavity seems to have had, in this region at least, a chitinous sheath on the dorsal side.
All the endopodites are of chitinous material, and the various specimens show, according to the perfection of their preservation, from four to six segments.
In the original of figure 5, plate 2, which seems to have been cut so as to cross the appendages at their line of junction with the ventral membrane, there appear to be narrow chitinous (?
No chitinous lining of the stomodaeum or proctodaeum was found, but it is not certain that any of the sections cut either of those regions.
It appears that it extended into the thorax, and that above it and the heart was a chitinous dorsal sheath.
That life might be very long indeed; in the nutrient tank beside Tropile's, as it happened, lay a Component with eight legs and a chitinous fringe around its eyes.
Its ropy arms and legs were covered with fine chitinous spines, laid on as close as hairs in a pelt, and sharp as thorns.
The other four groups of segmented animals possess in common the feature of jointed appendages and a covering of chitinous plates, and are brought together under the term Arthropoda.
They should be preserved in alcohol, and on account of their usually strong chitinous covering, precautions as to the strength of the alcohol are less necessary here than with softer-bodied specimens.
For further special directions for mounting, for microscopic purposes, different insects and the different parts of insects, representing both the external chitinous covering and the internal anatomy, the student is referred to special works.
Worms differ from the other four groups in having no articulated appendages, and in having a soft body-wall or integument instead of a dense chitinous covering, and are separated as a special class Vermes.
The vibrations set up in the membranous tympanum stimulate terminal nerve organs at the ends of chitinous processes, placed in a cavity bounded externally by the tympanic membrane.
In many terrestrial Insects a different type of auditory organ has been met with, consisting of a portion of the integument modified to form a tympanum or drum, and supported at its edge by a chitinous ring.
On the course of the terminal nerve-fibres, between the nerve-cell and their entrance into the porous chitinous canal, Graber describes the existence of rods or scolophores.
At the base of the modified chitinous layer a series of cells is seen, many, if not all, of which belong to the chitinogenous layer.
The chitinous layer is composed of the usual three zones of the Limulus surface--externally (Fig.
The gut of the arthropod is lined with a thin layer of chitin, which is traversed, like all other chitinous surfaces, by fine canaliculi.
Each goblet possesses a central pore, which is the termination of a very fine, very tortuous, very brittle chitinous tubule (ch.
The fine tubule is soon lost in the thickened but soft modification of the chitinous layer (ch.
In this chitinous layer the special sense-organs are found.
This cuticle corresponds to the chitinous covering of the arthropod, and like it is perforated with canaliculi, and, according to Lwoff, possibly contains chitin.
A stomach armed with chitinous or shelly plates or teeth, as in certain insects and mollusks.
These hydroids form, by their rootstalks, a firm, chitinouscoating on shells and stones, and esp.
A slender outgrowth from the chitinous cuticle of insects, spiders, crustaceans, and other invertebrates.
An inner cellular layer which lies beneath the chitinous cuticle of arthropods, annelids, and some other invertebrates.
An air-tube consists of an epithelium of large polygonal cells with a thin basement-membrane externally and a chitinous layer internally, the last-named being continuous with the outer cuticle.
These spiracles have firm chitinous edges, and can be closed by valves moved by special muscles.
The head is usually connected with the thorax by a distinct membranous neck, strengthened in the more generalized orders with small chitinous plates (cervical sclerites).
The origin of the mid-gut (mesenteron), that has no chitinous lining in the developed insect, is the disputed point.
The family Onychoteuthidae is remarkable for the formidable chitinous hooks borne on the arms.
The suckers bearchitinous rings which are toothed along the outer edge.
These hooks are special modifications of the toothed chitinous ring which covers the sucker-rim in the Decapoda generally.
In this species the shell is a well-developed chitinous pen or gladius with a thickened axis narrowing to a point behind, but bearing posteriorly a wide thin plate on each side.
The chitinous chaetae have their origin in special ectodermal pits, at the base of which is one large cell which is thought to secrete the chaeta, as in Chaetopods.
The free edges of the mantle often bear chitinous bristles or setae which project beyond the shell.
A hard chitinous or calcareous process or corpuscle, especially a spicule of the Alcyonaria.
One of the movable chitinous spines or hooks of an annelid.
The hard calcareous or chitinous external covering of mollusks, crustaceans, and some other invertebrates.
It is better for the insect to have a chitinous covering.
The insects have muscles inside their chitinous shells.
They are broad, fanlike organs formed of a double membrane and strengthened by chitinous veins or nervures.
One of the peculiar minute chitinoushooks found in large numbers in the tori of tubicolous annelids belonging to the Uncinata.
They have an oblong, disklike body, supported by a thinchitinous plate, from which rises a thin diagonal crest which acts as a sail.
The chitinous shell is hyaline and plastic to a slight extent, so that the body is capable of some change in shape.
Medium-sized ciliates, inclosed in a chitinous lorica with embedded sand crystals.
Beyond the buccal mass, food passes into the esophagus, which widens out into a muscular pouch or stomach; this may also be provided withchitinous teeth or hard knobs or plates for the purpose of further triturating the food.
Lingual ribbon^: The chitinous band of teeth, or rasp, borne upon the odontophore; the radula.
The indirectly protected group includes those spiders which are rendered inedible by the possession of sharp spines and chitinous plates, and also those that mimic other specially protected creatures.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "chitinous" in a variety of sentences. We hope that you will now be able to make sentences using this word.
