80 



NOTES ON THE SALlVAUY-GLANDS 

 AND SYRINGE OF TWO SP. HEMIPTERA 



by J.-t\ liorslinw F. Z. S. 



The following notes refer to Pristhesancus papueusis StAl, a 

 carnivorous liug from N. Qiieensland, where it is exceedingly 

 coininon ; and Enectus elongatus Dist., a phytopliagous sp. from 

 the sanie dislrict, where it is not at ail comnion, and appeared to 

 feed on but one or two kinds of tree. The salivary-glands, however, 

 of Spliedanolesles moidicus StAl a carnivorous Bug from S. China, 

 are almost identical with those of Pristliesancus papuensis. 



In the embryo the salivary syringe appears to arise as a dilatation 



ordiverticulum atthe junc- 

 tion of the two salivary 

 ducts (c, fig. i). It seenis 

 to be a part of the salivary 

 ducts and like Ihem is trans- 

 versely striated, which is 

 quite évident in the earlier 

 stages before the syringe 

 bas become heavily chiti- 

 nised (a, fig. 1). Powerful 

 retractor muscles attach to 

 thchirgerandclosed end of thediverticulum,andatalaterembryonic 

 stage this end is invagi nated to form the plunger or piston (b, lig. 1), 

 whilsttheouter wallor syringe barrelbecomesverychitinousandhard. 



In the adult Bug the 

 wallofthesyringe-bar- 

 rel (pb, fig. 2) where 

 the saiivai'y-dwcts en- 

 ter (jsd) is bulgOil oui 

 wards, forming a sub- 

 trianguiar recess in 



the interior, over 

 which lies a less hea- 

 vily cliitinised fold froin the 

 wall just at — and parti y 

 forming — the cntrance of 

 the ducts. This told acts as 

 a valve (V), opening inwards 

 when the retraction of the 



plunger(p) causes a vacuum -^ ^v p 



in the syringe-barrel and Z, 



the saliva tlows in, and closing when the retractor muscles (m) 



