262 HANDBOOK OF INVERTEBRATE ZOOLOGY. 



triculus, which lies over the figure 3* in Fig. 139, is not 

 sharply separated from the ingluvies. 



5. Running back from the posterior end of the proven- 

 triculus to the seventh abdominal segment is a lar-e cvlin- 



D / 



drical pouch, the ventriculus (Fig. 139, vri). Its anterior 

 end is about as large as the posterior end of the proven- 

 triculus, and its posterior end is much smaller. 



6. Surrounding the spot where these two chambers join 

 each other are sixteen transparent, cone-shaped pouches, 

 the gastric coeca (Fig. 139, pp), placed base to base in 

 such a way as to form a belt of eight fusiform pouches 

 around the digestive tract. If the trachea 1 which bind 

 them to the digestive tract are dissected away, it will be 

 found that the pointed ends are free, eight of them running 

 forwards on the sides of the proventriculus and ei^ht 

 backwards on the ventriculus. 



7. Occupying the seventh, eighth and ninth abdominal 

 segments is the ilium (Fig. 139, tl), much smaller than 

 the ventriculus, cylindrical, and abruptly constricted pos- 

 teriorly, where it joins the small intestine or colon. 



8. Twisted around the ilium are great numbers of small 

 white tubes, the malpighian tubes (Fig. 139, m), which 

 open into the ilium where it joins the ventriculus. 



9. The colon, or small intestine (Fig. 139, co), is a 

 delicate light-colored tube, which originates at the pos- 

 terior end of the ilium, and bends abruptly upwards 

 towards the dorsal surface, where it abruptly enlarges to 

 form 



10. The rectum (Fig. 139, ?), a small white sacculated 

 pouch, which lies directly before the terga of the ninth 

 and tenth segments. 



11. The rectum opens at the anus, which lies between 

 the bases of the podical plates, on the lower surface of 

 the eleventh tergum. 



