6 TKU I.AI) TIKHKMAKIA FRDM INDIAN TIBET 



L 21.^ Pool just IkIow Ilimis Goiipa, icnipcrature 9.5 C, o500 meters, June lith, 

 1932. Contains four specimens of Polycelis, asexual. 



L25. Stream above Leli, temperature /.S-S.G^C., 3570 meters, June 21st, 1932. Si.x 

 specimens of Pol\ccIis of which two were obviously in the sexual state. These were removed 

 and sectioned and furnish the main basis for the taxonomic description. 



L 34. Pool, Bao, temperature 20.8 C, 4585 meters, June 2Sth, 1932. This vial con- 

 tains one Polycelis and three small specimens which are probably rhabdocoels. 



L35. Springs, four miles from Bao, temperature 7.2 C, 41 meters, June 26th, 1932, 

 Five good sized but asexual specimens of Polycelis. 



L 60. Stream, under stones, Kyam, 4725 meters, July 21st, 1932. Allhoui^h the sev- 

 eral specimens of Pulxcclis in tiiis vial are the lar.nest in the cnllection they appear to be in 

 the asexual state. 



L 75. Springs, Tukmuru T.so, temperature IOC, 4385 meters, August 11th, 1932. 

 Seven rather small specimens of Polycelis. 



Search through the literature revealed the fact that this Polycelis had Ijeen seen before. 

 A number of specimens were taken in the expedition for collecting the aquatic animals of 

 Tibet made by Captain F. H. Stewart in 1907. The planarians of this collection were turned 

 over to Meixner and Muth who publishetl their report in 1911. They described and figured 

 the external features of the specimens, giving several drawings of the arrangement of the 

 eyes, and placed them in the genus Sorocclis. Owing to variations in the disposition of the 

 eyes these authors were inclined to think that the material consisted of more than one species. 

 Their specimens came from streams at Te-ring Gompa, 14,000 feet, and High Hill Gompa 

 above Gyantse, 14,500 feet. This form was again mentioned by Muth (1912j as similar to 

 his Sorocclis cbitntca from the region of I^ake Aral. Owing to a lack of sexual specimens, 

 Meixner and Muth were unable to furnish a diagnosis of the Tibetan material. 



The genus Sorocclis was until recently a badly defined genus into which were thrust a 

 number of many-eyed fresh-water triclads collected chiefly in Asia. In 1930 Kenk, in his 

 invaluable re-vision of the genera of the fresh-water planarians, proposed to limit this genus 

 to many-eyed f(n-nis belonging to the family Dendrocoelidae. Those which from the arrange- 

 ment of the inner muscular layers of the pharyn.x fall into the family Planariidae he has rightly 

 transferred to the genus Polycelis. The Tibetan specimens at my disposal belong to the family 

 Planariidae and the sexual apparatus corresponds in all respects to Kenk's definition of the 

 genus Polycelis. I therefore have no hesitation in placing them in that genus. It is also rea- 

 sonably certain that my specimens are the same as those recorded by Meixner and Muth. I 

 do not, however, agree with their supposition that more than one species is concerned. It 

 is true that the eyes are somewhat variable in different specimens, but these variations are 

 partly correlated with age and in any case are insufficient to serve as specific distinctions. To 

 the best of my knowledge, the above references constitute the only records of the Tiljetan 

 Polycelis. Study of the sexual apparatus shows that the form does not correspond to any 

 described species of Polycelis, and consecpiently I consider it a new species which fmni its 

 habitat I name Polvcelis iibetica. 



