16 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 124 



of planarians that I had received were collected by the Ekman dredge 

 method. According to my experience, Bdellocephala annandalei Ijima 

 and Kaburaki, which inhabits Lake Biwa-ko in Middle Japan and is 

 one of the largest freshwater planarians of the world, was taken easily 

 with a dragnet used for Cliaenogobius annularis urotaenia and Gnath- 

 opogon elongatus, but collection of this planarian hardly can be 

 expected with the Ekman dredge (Kawakatsu, 1964). The chief food 

 of B. annandalei is Tubifex worms inhabiting the muddy bottom of 

 the lake (Gose, 1964). 



Phagocata nivea from Alaska is an unpigmented epigean species 

 with two eyes. It is a very interesting fact that a pigmented 2-eyed sub- 

 species of P. nivea occurs in the bottom fauna of Lake Tahoe. In the 

 North American freshwater planarian fauna, however, most of the 

 Phagocata species are white, and so the absence of pigment hi this 

 genus cannot be regarded as adaptive (Hyman, 1954). Phagocata 

 bursaperforata, which may be related to P. morgani and inhabits 

 granite outcrops in Georgia, and P. subterranea from Indiana caves, 

 which probably loses its eyes when adult, are the only white species 

 without eyes in the genus. On the other hand, in the planarian fauna of 

 the Japanese Islands, every subterranean Phagocata species known 

 up to the present is white or translucent with two small eyes (P. 

 albata Ichikawa and Kawakatsu, P. tenella Ichikawa and Kawakatsu, 

 P. papillifera (Ijima and Kaburaki), Phagocata species Ichikawa and 

 Kawakatsu of Tsushima Island), or translucent without eyes (Phago- 

 cata? species Ichikawa of Asahigawa, and several other undescribed 

 forms). The Japanese epigean Phagocata species always are pig- 

 mented — P. vivida (Ijima and Kaburaki), P. kawakatsui Okugawa, 

 P. teshirogii Ichikawa and Kawakatsu, P. iwamai Ichikawa and 

 Kawakatsu (Kawakatsu 1960, 1965a, b). 



A study of the present geographical distribution of planarian 

 species of the world suggests that Phagocata, Polycelis, and Dendro- 

 coelopsis are primarily Eurasian genera (Kawakatsu, 1965a). The 

 chorology of species belonging to these genera has been discussed 

 extensively: Phagocata species by Kenk (1943, 1953) and Kawakatsu 

 (1965a), Polycelis species by Kenk (1952, 1953) and Kawakatsu 

 (1965a), and Dendrocoelopsis species by Dahm (1960) and Kawakatsu 

 (1965a). The occurrence of Phagocata nivea tahoena and Dendro- 

 coelopsis hymanae in the Sierra Nevada Mountains may suggest that 

 Alaska and the western area of the United States were populated by 

 the proto-species migrating to these areas from Asia across the old 

 land bridge on the Bering Strait (Kawakatsu, 1965a, fig. 10). 



In the central and eastern states of North America, many species of 

 the family Kenkiidae (consisting of the three genera: Kenkia Hyman, 

 Sphalloplana de Beauchamp, and Speophila Hyman) have been 



