5 28 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, G-arman had, however, 



correctly described the structure of the 

 mouth ;^ he puts a different interpretation 

 V •- , \^j, , on the parts ; he points out that the 



",j' ^ y'l mandibles (j), so-called by Uzel, are at- 



^ « * '<» 7 tached to the maxillae, and he considers 



V;;* . that they are really jointed, and that 

 ^ T _^ , ^ , '■ ' 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 pioints oiit that 



''J; \ the labrum and endocraniuni are also 



* '^ I '' asymmetrical. We think Carman's 



'' ■ view a reasonable one, and may re- 



■•/i\. mark that dissimilarity of the man- 



™' dibles of the two sides is usual in 



Fig. 254. — Face (with base of -, , iiij.ii ' i-i i 



the autenuae) of Aeoiothrips Insccts, and that the mandiblcs may 

 fasciata. (After Uzel.) a, "be hoUow for sucking, as is shown by 



Labrum ; S, maxilla with its , , p tt i • • i mi 



palp (c) ; bi, terminal part of the larvae of Hemerobiides. There 

 vertex- near attachment of ^re usually three occUi, but they are 



mouth-parts ; a, membrane "^ ^ 



between maxilla and mentum ; absent in the entirely aptcrous forms. 



e, mentum ending in =, point rp^g ^-^ appear to Spring from 



near / ; g, membrane ot o ± r jr o 



attachment of the labial palp the dorsal Surface of the body, not 

 nieS^iiAl^S;:^ ft^o^ the sides; the anterior pair is 

 base of mandible ; I, chitin- always quite Separated from the pos- 



ous lever ; m, moutli-spine, x • j-i • i it 



with its thick basal part n, t^rior ; the wings are always slender, 

 and 0, its connection with sometimes Very slender ; in other re- 



the forehead, r, r : p, for- j_j_i i-i-i -i ii 



amen of muscle ; 's and t, spects they exhibit Considerable variety ; 

 points of infolding of vertex : sometimes the front pair are different 



u, a prolongation of the . . 



gena. m 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 meso thoracic, 2nd 



^ Bull. Essex Inst. xxii. 1890, p. 24 ; also Amer. Natural, xxx. 1896, p. 691. 



