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THYSANOPTERA 



(Fig. 254) found on the left side of the body, as probably an enor- 

 mous development of the epipharynx. Previous to the appearance 



of Uzel's work, Garman had, however, 

 correctly described the structure of the 

 mouth; 1 he puts a different interpretation 

 on the parts ; he points out that the 

 mandibles (J), so-called by Uzel, are at- 

 tached to the maxillae, and he considers 

 that they are really jointed, and that 

 they are lobes thereof; while the Mund- 

 stachel or piercer is, he considers, the 

 left mandible ; the corresponding struc- 

 ture of the other side being nearly 

 entirely absent. He points out that 

 the labrum and endocranium are also 

 asymmetrical. We think G-arman's 

 view a reasonable one, and may re- 

 mark that dissimilarity of the man- 

 dibles of the two sides is usual in 

 Insects, and that the mandibles may 

 be hollow for sucking, as is shown by 

 the larvae of Hemerobiides. There 

 are usually three ocelli, but they are 

 absent in the entirely apterous forms. 



The wings appear to spring from 

 the dorsal surface of the body, not 

 from the sides ; the anterior pair is 

 quite separated from the pos- 

 terior ; the wings are always slender, 

 sometimes very slender ; in other re- 

 spects they exhibit considerable variety ; 

 sometimes the front pair are different 

 in colour and consistence from the 

 other pair. The abdomen has ten seg- 

 ments, the last of which is often tubular in form. The peculiar 

 vesicular structures by which the feet are terminated are, during 

 movement, alternately distended and emptied, and have two hooks 

 or claws on the sides. The stigmata are extremely peculiar, 

 there being four pairs, the first being the mesothoracic, 2nd 

 1 Bull. Essex Inst. xxii. 1890, p. 24 ; also Amer. Natural, xxx. 1896, p. 591. 



Fig. 254.— Face (with base of 

 the antennae) of Aeolothrips 

 fasciata. (After Uzel.) a, 

 Labium ; h, maxilla with its 

 palp (c) ; hi, terminal part of 

 vertex near attachment of 

 mouth-parts ; d, membrane 

 between maxilla and mentuni ; 

 e, mentum ending in a point 

 near f ; g, membrane of 

 attachment of the labial palp 

 k ; i, ligula ; j, j the bristle- 

 like mandibles ; k, the thicker 

 base of mandible ; I, chitin- always 

 cms lever ; m, mouth-spine, 

 with its thick basal part n, 

 and 0, its connection with 

 the forehead, r, r ; p, for- 

 amen of muscle ; s and t, 

 points of infolding of vertex ; 

 u, a prolongation of the 

 gena. 



