1913] Kershaw — The Alimentary Canal of Flata and other Homoptera 17.5 



THE ALIMENTARY CANAL OF FLATA AND OTHER 



HOMOPTERA. 



By J. C. Kershaw, 

 Trinidad, B. W. I. 



In many of the Delphacidse and Fulgoridae there is a large food- 

 reservoir or crop whose anterior end penetrates the thorax and 

 often enters the head — in Pyrops and Dictyophorodelphax reaching 

 to the tip of the greatly produced epicranium. In the present 

 subject, Siphanta acuta Walker, a Flatid or Pcecillopterid the 

 reservoir is very large and, from its junction with the oesophagus 

 just within the abdomen, extends anteriorly above the oesophagus 

 through the thorax and practically fills the epicranium above 

 the brain. It also extends posteriorly — beneath the heart and 

 above the rest of the internal organs — almost to the tip of the 

 abdomen; when inflated it also spreads out laterally over the other 

 organs, and expands into every available space in the body -cavity, 

 and is then very irregular in contour, becoming much more shapely 

 when contracted or when dissected out of the insect. 



In the thoracic portion the reservoir possesses four rather large 

 but often irregularly shaped latero-ventral caeca or pouches 

 (fig. 3, ca), two on either side, which sometimes extend down- 

 wards into the cox» in a manner analogous to the mesenteric 

 caeca of spiders. Anterior to these caeca are two much smaller 

 latero-ventral caeca, one on either side; to the end of each caecum 

 a slender and rather long muscle is attached, the other end of the 

 muscle attaching to the lateral posterior margin of either side 

 of the prothorax. Occasionally the other caeca also possess 

 slender muscles which attach them to the body-walls, thus serving 

 to anchor the reservoir, but still allowing it plenty of freedom to 

 expand and contract. The reservoir, although tracheae ramify 

 over it as they do over the rest of the mesenteron, is not moored 

 by them to the body -walls. The tracheae are not shown in the 

 figures. 



This reservoir is an extension of the mesenteron and not of 

 the oesophagus, as appears by the character of its epithelium and 

 its development in the embryo. In the latter (figs. 1 and 2) 



