162 Transactions. — Zoology. 



it. This M. sylvestris, of Hutton, agrees very closely with 

 P. punctata, hut differs from it in the following points : (1.) It 

 is not so depressed, being nearly circular ; this may be due to 

 its poor preservation. (2.) The dorsal and ventral gaps in the 

 circle of chaetae are equal, and measure only twice the normal 

 gap, whereas in P. punctata the dorsal gap is four times the 

 normal. (3.) The prostomium is not entirely imbedded in the 

 1st segment ; it is possible that my specimens of P. punctata, 

 in which the prostomium appears to reach the 2nd segment, 

 had shrunk in preservation, so that the two segments approach 

 and hide the hinder edge of the 1st segment. (4.) There are 

 only three pairs instead of four pairs of sperm-sacs ;_ the first 

 pair is on the septum between 9 and 10, and pushes into both 

 these segments. (5.) The chaetae measure, on an average, 

 0-19 mm. ; the ventralmost couple, in sections, reaching 

 0-22 mm, ; and the smallest are 0'165 mm. 



From these facts it is difficult, at present, to determine 

 whether M. sylvestris is or is not identical with P. punctata, 

 for so long as only one species is known it is impossible to say 

 what are specific characters, and we must wait till further in- 

 formation about the genus is to hand. 



6. Megascolex lineatus. 



This was collected at Queenstown ; the single bottle con- 

 tains one entire individual and three broken specimens. All 

 are so soft that they break on handling. The length of the 

 complete individual is only l^in. (Hutton gives 2 in.— perhaps 

 for the living worm). The drawing of the prostomium is 

 wrong in representing it small ; it is more like that of the 

 preceding species. The chaetae are not in a continuous cu'cle, 

 but quite evidently in couples, as Hutton figures for M. 

 sylvestris ; in fact, the worm is an undoubted Plagiochata. 



If we may judge from the state of preservation, the pre- 

 sent species was more deeply pigmented than M. sylvestris, 

 for it is not so absolutely bleached by the spirit as that \yorm ; 

 it is, in fact, a very faint brown. The dorsal gap in the 

 circle of bristles measures three times, and the ventral gap 

 twice, a normal gap between two successive couples. 



This worm differs from P. punctata in the following 

 characters: (1.) The spermiducal pores are carried by pa- 

 pillee, and there is no defined ridge surrounding the ventral 

 area on which the pores lie (this may, of course, be due to 

 the preservation of the worm). (2.) The spermathecae have 

 two peculiar diverticula, instead of a single simple cylindrical 

 diverticulum; of these, one is an oval pouch, the other is 

 a three-lobed pouch with a narrow neck; the two pouches 

 open close together into the duct of the main sac. This is 

 a very definite specific character. (3.) The chaetae measure 



