566 NOTES ON AUSTRALIAN EARTHWORMS, 



more like xT. Camdenensis than a perichsete worm, though a closer 

 examination shews that it is provided with from 16 to 20 or more 

 rows of setae, which dorso-laterally are arranged somewhat irregu- 

 larly. Nevertheless, from the consideration of its general charac- 

 ters, at any rate provisionally, it is here included in the genus 

 Perichceta. The largest (spirit) specimen obtained measures 190 

 mm. in length, with a breadth of about 9 mm. in front and 7 mm. 

 further back, but other specimens of nearly the same length are 

 much less in diameter. Body cylindrical, often in spirit specimens 

 contracted just in front of clitellum where the mesenteries are 

 thin, and the intestine of small calibre ; diameter greatest in the 

 region in front of this where the mesenteries are thick ; flattened 

 somewhat ventrally, tapering very gradually posteriorly ; the 

 circumference of the last few segments decreases rapidly and 

 successively, and the anus is situated either on a central eminence, 

 or in the centre of a disc, according to the state of contraction. 



Prostomium somewhat flattened, marked anteriorly and inferiorly 

 with irregular grooves ; extending back on the buccal segment for 

 about \ its width. 



The segments of the posterior portion of the body are either 

 free from zonitic markings, or, like those in the middle region have 

 two, one in front of and one behind the ridge which carries the setae. 

 In the anterior region the number of annuli into which some of 

 the segments are divided is rather difficult to make out at first 

 sight. Segments n to iv are bi-annulate ; after these they are 

 either tri-annulate — the setae being on the middle annulus, or in 

 addition, as from about vn to xiii, the anterior and posterior 

 annuli may again be less completely sub-divided, each into two, 

 giving five annuli to a segment altogether. Many setae are 

 wanting in this region. 



The clitellum comprises 4 or 4J segments from xiv to xvu, or 

 in addition the posterior half of xiii. It varies in the extent in 

 to which it is developed, being sometimes very thick and complete 

 all round, or incomplete on the ventral surface of about the last 

 segment. A good-sized specimen 140 mm. long shews no trace 



