1913] Kershaw — The Alimentary Canal of Flata and other Homopfera 187 



In conclusion, I am indebted to Dr. H. Lyon, the pathologist 

 of this experiment station, for much information about the plants 

 on which these insects feed, especially with regard to the nature 

 of the vegetable juices which they imbibe. 



EXPLANATION OF FIGURES. 



1. Early embryo of Siphanta acuta. Fam. Hatidae. 



2. Later embryo of the same. 



3. Alimentary canal of the same. 



4. Details of the same. 



A = longitudinal section of mesenteron and oesophagus. 

 B = transverse section of same, through line a — b 

 C = longitudinal sections of ceaca of reservoir. 

 4a: 



D = longitudinal section of mesenteron and oesophagus of Perkinsiella sac- 

 char icida. 

 E = transverse section of same, through line a- — b. 



5. Transverse section of young stem of plant, showing setae of a mealybug 

 amongst tissues. 



6. Alimentary canal of Oliarus sp. Fam. Cixiidae. 



7. Alimentary canal of Dicfyophorodel phax mirabilis Sw., Fam. Delphacidae. 



8. Alimentary canal of Perkinsiella saccharicida Kirk., Fam. Delphacidse. 



9. Alimentary canal of Tricentrus cdbomaculatus Dist., Fam. Membraeidae. 



10. Alimentary canal of Aleyrodes sonchi Kot., Fam. Aleyrodidae. 



In all the figures of the alimentary canal the parts are more or less opened out, 

 so as to show clearly. 



LETTERING OF FIGURES. 



a = anus. ep = epithelium. 



abd = abdomen . f r = food-reservoir. 



bm = basement-membrane. f rm = food-reservoir muscles. 



br = brain. frv = food-reservoir valve. 



ca = caecum. g = genital opening. 



chi = chitinous intima. hd = head. 



cs = cardiac septum. hi = hind intestine. 



cu = cuticle. lit = heart. 



dm 1 = inner diagonal muscles of cesoph- lab = labium. 



agus. lm = longitudinal muscles. 



dm 2 = outer diagonal muscles of cesoph- he = lumen of oesophagus. 



agus. m = muscles, 



en = viscid fluid between epithelium and mes = mesothorax. 



peritrophic membrane, probably con- met = metathorax. 



taining the enzymes; only shown in mi = mid-intestine (midgut, mescnte- 



the figures in two or three places, to ron). 



keep them clear; except in figure 4a. mp = malpighian tubes. 



