74 



same author, possesses „il ventriglio mol to piccolo, cilindrico, poco piu 

 lungo che largo, situato nel segmento V." About P. sansibaricus is 

 recorded by Michaelsen „einen Muskelmagen konnte ich nicht finden, 

 im Segment XIII zeigt der Oesophagus eine fast kugelige Erweiterung." 

 As to the intestinal canal of P. gruenewaldi Michaelsen mentions 

 „der Darm modifiziert sich vorne zu einem drüsig-muskulösen Schlund- 

 kopf. Auf diesen folgt ein langer, enger, von einem Blutsinus innig 

 umspülter Oesophagus. Im Xlllem Segment zeigt der Oesophagus 

 eine fast kugelige Erweiterung, die sich durch die zottige Struktur 

 der Wandung und den Blutreichthum auszeichnet. Eine Ansammlung 

 von Kalkkonkrementen zwischen den Zotten der Wandung zeigt, dass 

 man es hier mit einem Homologon der Kalkdrüsen andrer Terricolen 

 zu thun hat. In XlVem Segment ist der Oesophagus auffallend glatt 

 und arm an Blutgefässen ; zugleich zeigt sich die Muskulatur der 

 Darm wandung hier etwas verstärkt, etwa bis zu einem Viertel der 

 Epitheldicke. Zweifelsohne is diese Modification des Oesophagus als 

 ein rudimentärer Muskelmagen anzusehen." I cannot entirely agree 

 with Michaelsen's statements, for I found in the examples of P. 

 gruenewaldi, which I could examine, also a rudimentary gizzard in 

 segment VI, and I believe , that it was overlooked by him ; as to the 

 presence of lime-concretions in the dilated region of the intestine in 

 segment XIII, I can quite confirm his observations. In P. violaceus 

 the intestinal canal shows also an annular dilatation in segment XIII , 

 but I did not observe any lime-concretions therein; however on tran- 

 verse sections a wide blood-lacuna is visible here in the intestinal 

 wall, which is highly folded and covered with a low epithelium. 



Each spermatheca consists of a large oval pouch, with a short 

 muscular duct, and a small, stalked, pyriform diverticulum; their 

 microscopical structure agrees with that of other allied worms, and 

 corresponds to the detailed description of the spermathecae of Plagio- 

 chaeta, recently published by Benham. The main pouch is totally fil- 

 led with a finely granular matter, produced by the tall columnar 

 epithelium ; at the side , lying next to the intestinal canal, the colum- 

 nar cells are not so high as those in the remaining portion of the pouch. 

 This fact , which I observed also in other spermathecae , is not recor- 

 ded by Benham. The diverticulum is entirely filled with spermatozoa. 



The prostata is a narrow, tongue-shaped body, superficially di- 

 vided in lobes, not extending beyond the XVIIIth segment; its 



