THE OPALIKID CILIATE IXFVSORIANS. 337 



Division i. 



C. lanceolata (p. 137) in Sana Asia." 



This species is not similar to any other Cepedea (fig. 102, p. 137). 

 no other species having so slenderly tapering a body posteriorly, or 

 having so few nuclei. Its form is much like that of a microgameto- 

 cyte. It resembles very young Cepedea dlmidi-ata in shape and in 

 its small number of nuclei. In body form and number of nuclei this 

 Cepedea resembles Protoopalina quadnnucleata, but the nuclei of the 

 former are Cepedea nuclei and the nuclei of the latter are Protoo- 

 palma nuclei. Cepedea lanceolata seems to be a transitional form 

 between the genera Protoopalina and Cepedea and is probably the 

 most archaic of the known Cepedeas, The highly evolved species of 

 Protoopalina (group 9), which approach the genus Cepedea^ and the 

 most archaic species of Cepedea {lanceolata) occur in the Malay 

 Islands and in "Asia." This is some indication that the genus 

 Cepedea arose in the general region of Malaysia or eastern Asia, but 

 there are other indications of its origin in India in post-Triassic 

 times, after Australia had broken away from Equatoria (figs. 233 

 and 234). This suggestion of eastern origin is somewhat em- 

 phasized by the fact, already mentioned, that two-thirds of the 

 known species in the genus are now living in the eastern hemisphere. 

 The absence from Australia of transitional species between the two 

 genera and of all species of Cepedea is an indication that the genus 

 Cepedea evolved since Australia separated from Equatoria. It 

 seems clearl}^ to be a more modern genus than Protoopalina. 



Division 2 (fig. 250). 



C. dimidiata (p. 139) in Rana and Bufo. Europe, eastern Asia, 



C. dimidiata hawaiiensis (p. 143).. in Rana Hawaii, introduced. 



C. dimidiata ori entails (p.l41) in Rana Japan. 



C. dimidiata [paraguemsis] in Hyla Paraguay. 



(p. 142). 



C. saharana (p. 144) in Rana northern Africa. 



C. buergeri (p. 145) in Polypedates ( Raninae . Japan. 



C. buergeri sinensis (p. 146) _..in Bufo southern China. 



C. minor (p. 147) in Alytes Discoglossidae. France. 



All but the last named of the species of this division have in- 

 dividuals of two forms, stocky and slender, and in all regards they 

 are considerably alike. The affinities of Cepedea minor are doubt- 

 ful and it should probably be left out of account in the discussion 

 of distribution. Excepting the Paraguayan form, which is classed 

 as a subspecies of C. dimidiata and the Hawaiian form which must 

 have been introduced by man, the other members of the group all 

 belong to the one zoogeographical region including Asia north of 

 the Himalayas, Europe, and northern Africa, the latter of which 

 zoogeographically may be considered almost a part of Europe. 



