ON CRISTISPIEA YENEEIS NOT. SPEC, 



5o: 



On Cristispira veneris nov. spec, and the 

 Aflanities and Classification of Spiroclisets. 



By 



C. (iitloid Do1>ell, 



Fellow of Trinity College. Camljridge ; Lecturer at the Imperial 

 College o£ Science and Technology. London. 



With Plate 20 and 2 Text-figures. 



Contents. 



Introduction 



Material and Methods 



Occurrence of Micro-organisms in the Cry 



Lamellil)ranchs 

 Cristispira veneris n. «p. 



(1) Structure 



(2) Division 

 The Morphology, Affinities, and Classification 

 Literature References 

 Description of Plate 



stalline Styles of 



of Spirochtets 



PAGE 



507 

 508 



511 

 514 

 515 

 525 



527 

 5:'.9 

 540 



Inteoduction. 



Dltking the last few year.s many memoirs have made their 

 appearance in connection Avith the remarkable group of 

 Protista which may be conveniently collected under the 

 common name " Spirochtets.^' Of these organisms the most 

 divergent descriptions have been given^ and consequently 

 the most divergent views have been held regarding their 

 affinities with other organisms. Many workers consider that 



VOL. 56, part 3. NEW^ SERIES. 35 



