. A textbook of invertebrate morphology [microform]. Invertebrates; Morphology (Animals); Invertébrés; Morphologie (Animaux). 620 INVERTEBRATE MORPHOLOGY. metathoracic pair being usually represented by a pair of club- shaped bodies on the sides of the segment, termed hcdteres or balancers. The wings are always trans- parent and the veins by no means abundant. In a few forms, such as the Sheep-tick (Melophagus) and the Flejis {Ihdex), the wings are entirely wanting,' in harmony with the parasitic habits which these forms possess, but they form exceptions to the general rule. The mouth-parts are
. A textbook of invertebrate morphology [microform]. Invertebrates; Morphology (Animals); Invertébrés; Morphologie (Animaux). 620 INVERTEBRATE MORPHOLOGY. metathoracic pair being usually represented by a pair of club- shaped bodies on the sides of the segment, termed hcdteres or balancers. The wings are always trans- parent and the veins by no means abundant. In a few forms, such as the Sheep-tick (Melophagus) and the Flejis {Ihdex), the wings are entirely wanting,' in harmony with the parasitic habits which these forms possess, but they form exceptions to the general rule. The mouth-parts are adapted for sucking and also for piercing; the labruxn (Fig. 245, Ir) and labium {la) are prolonged into grooved processes, forming together a tube within which lie, in the female Mosquitoes (Oulex) and Gadflies (Tabanus), two pairs of elongated needlelike rods which repre- sent the mandibles (md) and maxillio (mx), to which a lifth unpaired stylet may be added which arises as a growth from the lower wall of the pharynx {hy). In other forms the maxillae only OF A Gnat, Culex, the ^^^.ve the ucicular form, the mandibles Labrum turned to fusing with the labrum, and in all cases ONE SIDE (fro,u the maxillary palps are present, whil,> the labial palps are undeveloped, lu the ordinary House-fly (Mtisca) the ex- tremity of the sucking-tube is expanded into a disklike structure, and in all forms the salivary glands open near the extremity of the tube, usually niaggotlike (Fig. 244), entirely destitute of feet, and in some forms the head even is indis- tinguishable. The metamorphosis is complete, the pupa boiiig in the Mosquitoes active, swimming about in water, thou^^h more usually it is incapable of motion, and enclosed witliiu the last larval skin, thus belonging to the coarctata Fig. 245.—Mouth-parts WIG) hy = hypopharyux, a process of labium. I'i = liibiuin. Ir = labium. md — mandible. 7IU --= maxilla). p — maxilliiry palp. The larva) are. Please note t
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishernewyo, bookyear1896
