ON MEGASCOLBX CCERULEUS. 57 



the worm and assist it in burrowing. The conical shape of 

 these anterior septa may be gathered from fig. 3. 



Alimentary Tract. 



I have little to add in this respect to Beddard's account for 

 '' Pleurochseta.^^ I diflFer from him slightly with regard to the 

 enumeration of the segments. 



The arrangement of the anterior portion of the alimentary- 

 canal is shown in fig. 3. 



The pharynx is bounded posteriorly by septum iv . v. This 

 statement is not intended to exclude the possibility of there 

 being thin, more anterior septa passing behind it. Numerous, 

 doubtless unicellular glands lie outside on the walls of the 

 pharynx, and open into it in the dorsal region. 



The gizzard consists of an anterior thin-walled portion and 

 a posterior thick- walled portion. Both portions are contained 

 in the same segment. The former bears, projecting into its 

 lumen, numerous hair-like processes which are lined by chitin 

 and doubtless serve as a strainer. I am not aware that any 

 such arrangement has been described in any other worm. 

 The latter has a very thick muscular wall, and this is lined 

 internally by thick, hard chitin. Following the gizzard is a 

 narrow portion of the oesophagus, which extends from segment 

 VI to ix.^ 



There is no specially large blood supply in the walls of the 

 portion of the canal above described. 



Segments x to xv contain the calciferous glands. In each 

 of these segments the canal is swollen out into a bulb-like 

 form, so that there is a series of such swellings, and between 

 them in the region of the septa there are constrictions. I 

 call these dilated portions of the oesophagus, calciferous glands, 

 because there may usually be found in them smaller and 

 larger concretions of carbonate of lime."^ 



1 I use for the present the term oesophagus for any portion of the alimen- 

 tary tract which lies anteriorly to the large intestine, and is not designated by 

 any special name — as, for instance, pharynx or gizzard. ' 



- I sent a number of these concretions to Professor W. D. Halliburton, of 



