ii6 THE APODID^: PARTI 



fine circular bands of transversely striated muscles. 

 We find here a striking resemblance with the mid-gut 

 of many carnivorous Annelids. 



The mid-gut passes gradually into the hind-gut ; it 

 is very difficult to fix upon the exact place where the 

 chitinous intima of the latter commences. In passing 

 from one to the other, the muscular layer is more 

 and more developed ; the epithelium gradually 

 changes, becoming more and more a glandular 

 epithelium, with large round glandular cells arranged 

 in great numbers, and pouring their contents through 

 pores l in the chitinous intima into the hind-gut. From 

 the position of these glands we are fairly safe in con- 

 cluding that they are excretory. 



In the anal segment the rectum is attached to the 

 body wall by radiating muscles, which act as dilators, 

 while the strong circular muscles keep it closed. As 

 in the oesophagus, the wall of the rectum is thrown 

 into folds, which run longitudinally. The anus is 

 situated at the extreme end of the body under the 

 caudal plate, where such a plate is present, and 

 between the caudal cirri or cercopoda. 



1 The actual existence of these pores we have not, however, been able 

 to demonstrate. 



