OPALINID CILIATE INFUSORIANS — METCALF 



571 



archaic subgenus. There is no sharp demarcation. Some species 

 have formae less elongated and others slender and with naked spines 

 (P. caudata) and so almost grade into this subgenus. The species 

 that are undoubtedly of this archaic subgenus I are all of southern 

 distribution, Patagonia, Australasia, and southern or tropical Africa. 

 P. saturnalis, from Mediterranean fish, shows much resemblance. 



Protoopalina, Subgeneric Group I {fig. 128) 



P. diplocarya Metcalf, in a leptodactylid, Straits of Magellan. 

 P. papuensis Metcalf, in a Hyla, Dutch Papua. 

 P. acuta (Raff), in a leptodactylid, Australia. 



P. xenopodos Metcalf, in Xenopus, Belgian Congo and South Africa. 

 P. [capensis, new species], in a doubtful leptodactylid. Cape Colony, South 

 Africa. 



P. appendiculata Fantham, in a Rana, South Africa, 

 P. australis, new species, in a Hyla, Australia. 



P. africana Metcalf, in a ranid, the Cameroons. 



P. nutti Metcalf, in a Rana, British East Africa. 



P. saturnalis (Leger and Duboscq), in a teleost, Mediterranean Sea. 



P. stevensoni Metcalf, in a Bufo, Sudan, Africa. 



Figure 128.— Geographic distribution of Protoopalina, subgeneric group 1. 



The last four species (Metcalf, 1923a, group 2) are less elongated 

 posteriorly than the others, but resemble them. The sub-Antarctic 

 and tropical African distribution of this subgenus indicates that the 

 genus was of southern origin, doubtless in primitive Anura, m the 

 Triassic, Southern Hemisphere, land mass that I have called Equa- 

 toria, including Gondwanaland and South America. This archaic 

 subgenus has not spread beyond the limits of its ancestral home. 



