OPALINID CILIATE INFUSORIANS — METCALF 



573 



discoglossids there formerly, e. g., the ancestors of the New Zealand 

 Liopelma (Metcalf, 1928a). The spread of Ascaphus to North 

 America, with its Protoopalina of this subgenus, occurred in the 

 Cretaceous period (c/. p. 592). The subgenus is as old as the Jurassic 

 period, for it is in Austraha, and Liopelma, a former host, now barren 

 because of lack of an aquatic, larval stage, is in New Zealand. 



Protoopalina, Suhgeneric Group III (Group 5 of Metcalf, l92Sa) (jig. ISO) 



P. montana Metcalf, in a pelobatid, Java. 



P. adelaidensis Metcalf, in a Hyla, eastern Australia. 





FiGUKE 130.— Geographic distribution of Protoopttlina, subgeneric group in. 



These are very similar to each other and are but shghtly demarcated 

 from group II. Their occurrence, one in Java and one in Austraha, 

 agrees with Arldt's conclusion that Java and Australia remained 

 connected through the early Cretaceous after they had separated 

 from Asia and western Malas^^sia. 



Protoopalina, Suhgeneric Group IV {Group 6 of Metcalf, 192Sa) (Jig. ISl) 



P. jiliformis Metcalf, in a Rana, Formosa. 



P. tenuis (Raff), in a leptodactylid, eastern Australia. 



These elongated forms show some resemblance to the less elongated 

 species P. africana and P. borneonensis. They apparently evolved 

 at a time before Formosa and Austraha definitely parted company, 

 which means probably in the Jurassic period. Tropical Africa and 

 Borneo probably had connection with both Australia and Formosa 

 at that time. 



