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PROCEEDINGS OF THE NATIONAL MUSEUM 



TOL. 87 



(1) That Bujo, having adopted Cepedea from its ranid hosts, possibly 

 Polypedates, in Asia, entered South America from eastern Asia by 

 some route not including North America and Central America, i. e., 

 by the circum-Pacific land-strip, before the close of the Cretaceous 

 period; (2) that in Tertiary times, when this land-strip fused with 

 western North America, Bufo entered that continent and later 

 adopted Opalina, as it adopts any opalinid when it meets it; (3) that 

 broad Opalinae evolved from Cepedea in some region not connected 

 with eastern Asia-Malaysia before Bufo's migration to America, i. e., 



Figure 137.— Geographic distribution of Cepedea. 



probably in Ethiopia-Lemuria; (4) that Opalina, late in the Tertiary, 

 in ranid hosts, entered eastern Asia when the Indian island fused 

 with Asia, and that it passed on, in Rana, to Siberia and Alaska and 

 down the Pacific coast of North America, west of the mountains, as 

 far as Central America, but did not go on to South America in spite 

 of a route being open via the Isthmus after the middle Phocene; (5) 

 that the Opalinae latae met hylids for the first time in Central America 

 after the middle Pliocene when they passed northward over the 

 Isthmus of Panama, were then adopted by them, and were changed 

 into the narrow form, Opalinae angustae, and were carried by these 

 new hosts northward throughout North America, infecting on the way 

 other Anura. One species, Hyla arborea, crossed to Siberia and more 

 southern Asia and with its American, narrow Opalina (obtrigona) 

 passed on to western Europe and even to northern Africa (see the 

 discussion of the HyHdae). H. arborea has evolved several subspecies 

 (usually recognized as species) 



