ADDITIONAL BRISTLES. 



69 



some sijecimens of Gl. fusca, an extr<a binstlc between the 

 ordinary marginal and the apical. 



Out of the material examined certain specimens, belonging to 

 GL morsitans, Westw., Gl. palUdipes, Austen, and Gl. palpalis, 

 ll.-Desv., show an additional small bristle in advance and a little 

 to the outside of the intra-alar : whether this bristle should be 

 regarded as belonging to the intra-alar or to the supra-alar series 

 T am unable to determine. In Gl. longipennis, Gl. fusca, and 

 (less clearly) in Gl. pallidipes an incomplete circlet of short 

 stoutish bristles (not shown in the figure) can be seen on the 

 anterior margin of the dorsum of the thorax between the 



Treesuturel dorso-central Bristle^ 

 PrcBSutural Bristle-^_ 



Humeral _^_^ 

 Bristles '"-"■-■ 



HotcpleurgI 

 Bristles. 



Prothcracic .,■ 



Stigma ■'' 



Prclharacic yy' 

 Bristle -y' 



Stigmstic Bristle 



fBecKer. Berl Ent.Z. 



xx^ixfiea-fj.p.Bl.) /,■' ^' 



/lesop/eural Bristles ''' / 

 Anterior Sternopleur'al Bristle 



Supra-alar Bristle 2'"''cforsocentrai Bristle 



Intra-alar Bristle / 7" dorse-centra/ 

 ■-" Brittle 



Scciiellar Bristles 



marginal and Bpical.) 



. fbst-glar 



Bristles 



BaseoJ ojing 



/,' Posterior Sternopleurs I Bristles 



/Pteropleural Bristles 



Fig. 11. 



Diagram of thoracic chrctotaxy of Glossina, pleural aspect (X 10). 

 N.B. There are no bristles on the hypopleura (the region above the last two jjairs of 

 coxa;) in Glossina, though Osten Sacken writes (Trans. Ent. Soc. Lond., 1884, p. .513) : — 

 " Most of the Calyptrata, except the Anthoniyiche, h.ave a tuft or row of bristles on the 

 hypopleura, a region which is destitute of them in the other families of Diptera."— 

 See also Girschner, "Beitrag zur Systematik der Musclden:" Berliner Eiitomolo- 

 gische Zeitschrift, Bd. xxxviii. (1893), pp. 297-298. According to Girschner's arrange- 

 ment, Glossiiw, belongs to the group Muscina; of his "Family Anthomyidsc." 



humeral callosities. These bristles are frequently difficult to 

 distinguish owing to the shadow between the head and the 

 thorax. There are usually three bristles on each side, close to 

 the humeral callosity, while a bristle on each side of the median 

 line would appear to belong to the inner dorso-central series. 



The relative size of the various bristles enumerated above is 

 roughly indicated in the diagrams by the size of the dots. 

 Generally speaking the largest bristles are the lowest humeral, 

 the notoplcural, supra-alar, post-alai-, the bristles of the transverso 



