Austrcdian Eo/rtlncomis. 61 



rhythmically contractile, circularly disposed, and which may 

 be (1) all connected with the dorsal, or (2) some only and 

 some with the supra-intestinal, or (3) some with the dorsal 

 vessel only and some with both. He calls the first lateral ; 

 those which only connect with the Supra-intestinal, Intestinal ; 

 and those which connect with both Latero-intestinal. I have 

 kept the word Heart for only those vessels Avhich arise from 

 the Supra-intestinal, and pass to the ventral, with or without 

 branches from the dorsal (except in the case of D. daval/ia, 

 where sections would probably shoAv the connections between 

 dorsal and supra-intestinal), and have called those passing 

 from the dorsal to the ventral anterior to these, anterior com- 

 missural vessels. These Benham (5) also calls '' lateral hearts." 

 My supra-intestinal evidently corresponds to Bourne's dorso- 

 intestinal, while those vessels at the extreme anterior end, which 

 break up without joining the ventral, belong to his dorso- 

 tegumentary system. In the post-cephalic region (Bourne 11, 

 note page 73) the branches may be posterior commissural, or 

 dorso-intestinal, or tegumentary, the chief difference being, in 

 those specimens I have examined, that the anterior one arise at 

 the posterior end of the segment, and the posterior from the 

 m.iddle. 



The generic names employed are those given by Beddard in his 

 " Monograph of the order Oligochaeta." 



1. — Megascolides gippslandicus, Spencer. 



Cryptodrilus gippslandicus, Spencer. P.R.S. Yict., 



1892. 

 Plate XIV.. Fi.o-s. 1, la, and Plate XVIL, Fig. 20. 



Dissect i ON. — The specimen examined was broken for some 

 distance behind segment 14. There is a double dorsal vessel 

 becoming single at the tail end, the two halves alternately join- 

 ing at the septa, and becoming divided on passing through 

 them in the anterior region, and running forward thus to the 

 front of segment 6, where they finally unite to form a single 

 vessel, which breaks up in the first segment. 



