OBSERVATIONS ON ORIODRILUS LAOUUM. 551 



Morphological and Biological Observations on 

 Criodrilus lacuum, Hoffmeister.^ 



By 



Dr. I<« Orley. 



Zoolog. Instit. University of Budapest. 



With Plate XXXVIII, figs. 1 to 8. 



In Vejdovsky^s very complete work, ' System und Mor- 

 phologie der Oligochaeten/ Prag., 1884, which bears the 

 character of a useful text-book on the morphology of the 

 Oligochaeta, I find only a scanty and incomplete account of 

 the very interesting terricolous form, Criodrilus. On pages 

 16 and 58 he says : " Lage der Hoden, Eierstocke, Samen- 

 leiter und Samentaschen, sowie Gurtels unbekannt.^' " Leider 

 weiss Man sehr wenig von dem Leben eines so merkwiirdigen 

 Oligochseten." I think that these assertions by this well- 

 known investigator justify me in publishing my own observa- 

 tions, incomplete though they are, relative to this worm. 



Criodrilus lacuum was discovered by the well-known 

 German zoologist Fritz Miiller, in 1844, iu the so-called 

 " Tegel-see," near Berlin, and in the following year was de- 

 scribed and figured by HofFmeister.^ It is almost incredible 

 that fully thirty years should have elapsed since its discovery 

 without its being found again. In 1876 this worm, found in 

 a branch of the Danube near Linz, was again mentioned by 



1 Translated from the MS. by Wm. B. Benham, B.Sc. 

 ^ ' Die bis jetzt bekannten Arten aus der Tam. der Regeuwiirmer,' Bruns- 

 wick, 1845, p. 41. 



VOL. ILXVir, PAKT 4. NEW SER. Q Q 



