Spiders on the contrary have no antennae, no separate head," an unsegmented abdomen and an additional pair of legs.
Here the males have one or the other of the first pair of antennae modified into a grasping organ for holding the female.
The sexes in Diptera are usually alike, though in a number of families with short antennae the males are distinguished by the fact that their eyes meet together (or nearly so) on the forehead.
The second antennae are usually the chief motororgans for swimming, walking and climbing.
The Dichelestiidae, on account of their sometimes many-jointed first antennae, are referred also to this tribe by Giesbrecht.
The antennae are short tubular extensions of the body wall, sometimes retractile with a depressed tip from which protrudes a tuft of fine stiff bristles.
Additional paired antennae may occur within the coronal surface, which is the seat of the sensory styles, of less complex structure, which occur in many genera.
A, Notholca longispina, lorica only; b, Anuraea aculeata, like the former, a floating pelagic type (plankton proper); c, Synchaeta stylata; corona with accessory antennae and sensory styles; auricles for swimming - an actively swimming pelagic type (nekton); d, Pterodina patina, with bdelloid corona and retractile foot with terminal ciliated cup; e, Distyla gissensis partly extended; f, Rattulus tigris.
The head is large, the neck slender, the antennae short and the legs longish, and the appearance of the long stalk-like waist of the ant is produced by a patch of whitish hair on each side of the forepart of the abdomen which has the effect of cutting away the parts of the segments so covered, leaving a narrow dark-coloured median area to represent the waist.
The antennae of these weevils are short and end in a knob; those of the Longicorns are very much larger, but the weevil-like look is produced by the presence of a knob-like swelling upon the third joint, the terminal portion of the antenna being so extremely fine as to be almost invisible.
Similar modification of the antennae in the Longicorn Estigmenida variabilis brings about the resemblance between this beetle and a beetle, Estigmena chinensis, one of the Phytophaga of the family Hispidae.
All insects have the same regional division of the body into head, thorax and abdomen, the same number of legs, a pair of antennae and a segmented abdomen.
The swords are leaf-shaped, with blunt points intended for cutting, not for thrusting; the hilts differ essentially from those of the Bronze Age, being shaped like a crescent to grasp the blade, with large pommels, or sometimes with antennae (the latter found also in Bavaria, Wurttemberg, Baden, Switzerland, the Pyrenees, Spain, north Italy): only six arrowheads (bronze) were found.
Other inventors had professed to find a solution of the problem by the use of looped receiving antennae or antennae inclined in various directions.
ANT-LION, the name given to neuropterous insects of the family Myrmeleonidae, with relatively short and apically clubbed antennae and four large densely reticulated wings in which the apical veins enclose regular oblong spaces.
The antennae of Diptera, which are also extremely important in classification, are thread-like in the more primitive families, such as the Tipulidae (daddy-long-legs), where they consist of a considerable number of joints, all of which except the first two, and sometimes also the last two, are similar in shape; in the more specialized families, such as the Tabanidae (horse-flies), Syrphidae (hover-flies) or Muscidae (house-flies, blue-bottles and their allies), the number of antennal joints is greatly reduced by coalescence, so that the antennae appear to consist of only three joints.
It is customary to divide the Orthorrhapha into the two divisions Nematocera and Brachycera, in the former of which the antennae are elongate and in a more or less primitive condition, as described above, while in the latter these organs are short, and, as already explained, apparently composed of only three joints.
- These singular crustaceans have long soft flexible bodies, the eyes stalked and movable, the first antennae small and filiform, the second lamellar in the female, in the male prehensile; this last character gives rise to some very fanciful developments.
In 1892 he distinguished the former as those in which the first antennae of the male have both members modified for holding the female, and the genital openings of the female have a ventral position, sometimes in close proximity, sometimes strongly lateral; the latter as those in which the first antennae of the male are similar to those of the female, the function of holding her being transferred to the male maxillipeds, while the genital openings of the female are dorsal, though at times strongly lateral.
Mayflies and dragon-flies danced in the sunlight; lizards darted across the paths; and legions of spiders pervaded the grass, many very beautiful - frosted - silver backs, or curious, like the saltigrades, who took a few steps and then gave a leap. There were crickets in infinite numbers; and flies innumerable, from slim daddy-long-legs to ponderous, black, hairy fellows known to science as Dejeaniae; hymenopterous insects in profusion, including our old friend the bishop of Ambato (possibly Dielis), in company with another formidable stinger, with chrome antennae, called by the natives ` the Devil '; and occasional Phasmas (caballo de palo) crawling painfully about, like animated twigs."
Of the corresponding pairs of appendages thirteen belong to the head and trunk, two pairs of antennae, one pair of mandibles, two pairs of maxillae, followed by three which may be all maxillipeds or may help to swell the number of trunk-legs to which the next five pairs belong.
Fleas are wingless insects, with a laterally compressed body, small and indistinctly separated head, and short thick antennae situated in cavities somewhat behind and above the simple eyes, which are always minute and sometimes absent.
It was then proposed to arrange a detector so that it was affected by the algebraic sum of the two oscillations, and by swivelling round the double receiving antennae to locate the direction of the sending station by finding out when the detector gave the best signal.
In his method three vertical antennae are employed, placed at equidistant distances, and oscillations are created in the three with a certain relative difference of phase.
Very valuable work in devising forms of antennae for directive radio-telegraphy has been done by MM.
It is said that 13,000 such olfactory organs are present on the feeler of a wasp, and 40,000 on the complex antennae of a male cockchafer.
The antennal segment apparently entirely disappears, with the exception of a pair of appendages it bears; these become the antennae; it is possible that the original segment, or some part of it, may even become a portion of the actual antennae.
The fact that the single pair of prae-oral appendages of trilobites, known only as yet in one genus, is in that particular case a pair of uni-ramose antennae - does not render the association of trilobites and Arachnids improbable.
Little is known of the form of the appendages in the lowest archaic Arachnida, but the tendency of those of the prosomatic somites has been (as in the Crustacea) to pass from a generalized bi-ramose or multi-ramose form to, that of uni-ramose antennae, chelae and walking legs.
The antennae, usually bottle-brush shaped (plumose) in the male sex, are less hairy in the female.
COCKROACH 1 (Blattidae), a family of orthopterous insects, distinguished by their flattened bodies, long thread-like antennae, and shining leathery integuments.
The first antennae have a lamellar appendage at the end of the peduncle, a decidedly non-entomostracan feature.
- In this division the body is partly covered by a broad shield, united in front with the head; the eyes are sessile, the first antennae are small, the second rudimentary or wanting; of the numerous feet, sometimes sixty-three pairs, exceeding the number of segments to which they are attached, the first pair are more or less unlike the rest, and in the female the eleventh have the epipod and exopod (flabellum and sub-apical lobe of Lankester) modified to form an ovisac. Development begins with a nauplius stage.
- Though concealed within the bivalved shellcover, the mouth-parts are nearly as in the Gymnophylla, but the flexing of the caudal part is in contrast, and the biramous second antennae correspond with what is only a larval character in the other phyllopods.
The title " branching horns " alludes to the second antennae, which are two-branched except in the females of Holopedium, with each branch setiferous, composed of only two to four joints.
2), or membranaceous and polished, hairy or smooth, oval or round or bean-shaped, or of some less simple pattern; the valves may fit neatly, or one overlap the other, their hinge may have teeth or be edentulous, and their front part may be excavated for the protrusion of the antennae or have no such " rostral sinus."
- First segment of hind-body footless, bearing the orifices of the genital organs (in the male unsymmetrically placed); last foot of the fore-body in the male a copulatory organ; neither, or only one, of the first pair of antennae in the male geniculating; cephalic limbs abundantly articulated and provided with many plumose setae; heart generally present.
In this tribe the males have both antennae of the first pair as sensory organs.
- The first segment of the hind-body almost always with rudimentary pair of feet; orifices of the genital organs (symmetrically placed in both sexes) in the following segment; neither the last foot of the fore-body nor the rudimentary feet just mentioned acting as a copulatory organ in the male; both or neither of the first pair of antennae in the male geniculating; cephalic limbs less abundantly articulated and with fewer plumose setae or none, but with hooks and clasping setae.
" Swimming Podoplea with geniculating first antennae in the male sex, and descendants of such; first antennae in female and male almost always differently articulated."
They are small insects, having straight antennae, and a compressed, usually very short abdomen with the second or second and third segments greatly developed, and the rest imbricated, and concealing the partially coiled ovipositor.
About twenty-seven species are now known, all characterized by length not excee 4 ding 06 of an inch, flat wings, three articulations in the antennae, one or two articulations in the tarses, with digitules, but without cornicles on the abdomen.