36 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



EXPLANATION OF PLATE IIL 

 Licnophora macfarlandi, sp. nov. 



Figs. 18-31. Successive division stages from glycerine preparations of mate- 

 rial killed with formalin or osmic vapor and stained with alum 

 carmine. Detail of cilia not represented. Zeiss, oc. 3, ob. D, 

 cam. (Figures reduced to two -thirds their original size.) 



Fig. 18. Ciliary field {cf) very small, macronuclei not yet united. 



Fig. 19. Ciliary field larger, macronuclei (%) uniting. 



Fig. 20. Ciliary field still larger, macronuclei united into irregular masses. 



Fig. 21. Ciliary field differentiated into a right spiral band {b.2), macronuclei 

 united into two bands, micronucleus enlarged and a short dis- 

 tance below the attachment cup, attachment disc increasing in 

 transverse diameter. 



Fig. 22. Secondary peristomal band elongating and unrolling, macronuclei 

 united into rounded masses; micronucleus on the border be- 

 tween neck and oral disc. 



Fig. 23. Secondary peristomal band still elongating and unrolling; macro- 

 nuclear masses elongated transversely — dumb-bell shape; micro- 

 nucleus just above the primary mouth. 



Fig. 24. Secondary peristomal band beginning to turn toward the left; 

 macronuclear masses approaching division; micronucleus divided, 

 one near the oral end of each peristomal band {n.^) (Division not 

 observed.); attachment disc beginning to divide; a distinct notch 

 between the two oral discs. 



Fig. 25. Secondary peristomal band turned toward the left, oral end on the 

 dorsal side; macronucleus nearly divided, ends lying along the 

 ciliary bands; attachment cup nearly divided. 



Fig. 26. Secondary band distinctly Iseotropic; nuclear bands extending 

 toward the attachment disc; the two attachment cups separated 

 by ingrowth of the inner row of cilia. 



Fig. 27. Oral end of secondary peristomal band appears on the ventral sur- 

 face of the daughter Licnophora, but is not yet twisted into a 

 mouth-opening; micronuclei in each attachment disc near the 

 adult position; two attachment cups fully developed; division 

 indentation between the two oral discs advancing. 



Fig. 28. Two LicnophorcB just separated, oral band of daughter animal [d) 

 showing the twist at the end, but the mouth and pharynx not yet 

 fully formed; micronuclei in usual position. 



Fig. 29. Young individual, perfect in every respect but still small and with 

 macronuclear bands not yet segmented. 



Fig. 30. Young individual of adult size, nuclear bands taking the position of 

 the segments of the resting stage. 



Fig. 31. Young individual showing segmentation of the nuclear band. 



