204 Mr. E. S. B agnail on neto Thysanoptera. 



each ornamented by a strong straight spine, which, with the 

 basal part, is about 0'7 the length of the segment bearing 

 them. The apical abdominal bristles are shorter and more 

 slender, especially the dorso-median pair on segment 10, 

 which are more slonder than the others, and shorter than the 

 corresponding pair on tergite 9, whereas in austrahs this 

 particular pair of bristles are the longest of all the apical 

 bristles. 



The comparative lengths of the abdominal bristles of the 

 two species are approximately as follows : — 



bispinosns. australis, 



Postero-marginal dorso-median pair, 9 . . . . 100 102 



„ 10.... 93 125 



Fair at posterior angles 9 90 100 



„ „ „ 10 ... . 90 100 



The stout spines of the abdominal segment 9 are a distinc- 

 tive feature — in fact, they may be regarded as unique in 

 known Terebrantian Thysanoptera. 



Type. In Coll. Bagnall, University Museum, Oxford. 



I/ah. W. Australia, Perth ; 1 ? with O. australis, sp. n. 



{E. D. Povlton). 



Odonlothrips australis, sp. n. 



2 . — Length about 1'3 mm. 



Colour dark chestnut-brown, fore-tibia? lighter and all tarsi 

 yellowish-brown ; fore-wings brown, with basal fifth or 

 thereabouts clear, though slightly tinged with light greyish- 

 brown towards anterior margin. Antennal segment 3 light 

 yellowish-brown, and a ring near base of 4 and 5 greyish to 

 practically colourless. 



Head approximately 1*22 times as broad as long. Cheeks 

 slightly swollen behind eyes and thence practically parallel, 

 posteriorly transversely striate ; eyes large and coarsely 

 facetted, occupying approximately 0'7 the total length of 

 head ; ocelli placed well back, posterior pair upon n line 

 drawn just above the posterior margins of eyes ; interocellar 

 bristles .short, placed immediately above the posterior ocelli. 

 Antenna' twice as long as the head, sense-cone on inner 

 surface of segment 6 (peculiar to the genu.-) normal. Rela- 

 tive lengths of segments 3 to 8 approximately as follows: — 

 54 : 51 : 36 : 52 : 7 : 11. Pronotuin apparently suborblcular, 

 a little longer than the head and about 1'45 times as broad 



