[Proc. Roy. Soc. Victoria, 22 (N.S.), Part II., 1909]. 



AiiT. XV II I. — Contributions to our Knoivledcjc of 

 A listralian Eartlvtvornis. 



The Alimentary Canal — Part I. 



By JANET W. RAFF, B.Sc. 



(With Plates XLVIII.-LI.). 

 [Read 9th December, 1909]. 



The following work has been undertaken at the suggestion of 

 Professor Spencer as a part of a general investigation into the 

 structure of Australian earthworms now being carried on in the 

 Biology Department of the Melbourne University. 



It deals with the structure of the alimentary canal in the fol- 

 lowing species, the generic names of which are those adopted by 

 Beddard in his " Monograplv of the Order of Oligochaeta," and in 

 Michaelsen's later work.^ 



1. Megascolex dorsalis. 



2. Megascolex fielder i. 



3. Megascolex tenax. 



4. Cryptodrilus saccarius. 



5. F I etcher odrilus unicus. 



6. Dijyorochcieta baker i. 



7. Biiiorochaeta tanjilensis. 



I have divided the work into two sections; the first dealing 

 with the structure of the canal, and the second with special 

 features in the different species examined. 



Section I. 



Oeneral Features. 



A. ^Macroscopic Structure. 



In dealing with the alimentary canal, J^eddard, whose nomen- 

 clature in regard to internal anatomy I largely follow, divides it 

 into the following parts, viz. : —(1) Mouth, (2) buccal cavity, 



1 Die fauna, Siidwost-AMstialiens," 1<)07. Oligochaeta. 



