STUDIES ON EARTHWORMS. 561 



Studies on Earthworms. 

 No. III. Criodrilus lacuum, Hoffmeister. 



By 



ITilliam Blaxland Benbam, B.Sc, 



Demonstrator in the Zoological Laboratory of University College, London. 



With Plate XXXVIII, figs. 9 to 19. 



Thanks to the kindness of Dr. Orley, who, at Professor Ray 

 Lankester's request, sent him a bottle containing a large 

 number of Criodrilus preserved in spirit, and including both 

 sexually mature and young specimens, as well as cocoons, I 

 have been enabled to make a study of this interesting worm. 

 The specimens are all in a good state of preservation, and I 

 have been able to add several new facts concerning its anatomy. 

 This is the first time that figures illustrating the general 

 anatomy of Criodrilus have been published. Hoff'meister^ gives 

 a coloured figure of the worm, and of the cocoon, showing 

 their natural size and appearance, bat with no details as to 

 setse, pores, &c. ; Vejdovsky^ has already published excellent 

 figures of various portions or organs of the worm ; e. g. the 

 ovary, nephridial funnel, setse, transverse section of the body, 

 so that I have not repeated these. Dr. Orley^ added drawings 

 of the prostomium, as well as of that of another worm which 

 he described as Criodrilus dubiosus; but in his paper, 

 published in the present number of this Journal^ he makes no 



' 'Die bis jetzt bekannt.Art. aus d. Fam.d.Regenwiirmer,' Brunswick, 1845. 



^ 'Systeme und Morph. d. Oiigochjeten,' Prag., 1884. 



^ ' Mathemat.u.Termeszt.tudomanyi Kozlemenyek,' Budapest, Bd.l6, 1881. 



