34 



PLATYHELMINTHES TURBELLARIA 



CHAP. 



these Triclads may creep over bridges of it, and may even be 

 blown from one stem or branch of a plant to another, hanging at 

 the ends of their threads. 1 



In Europe there are only two or three indigenous Land Plan- 



arians, of which Rhynchodemus 

 terrestris O. F. M. (Fig. 15, B) is 

 the most widely distributed, and 

 has been found in moist situa- 

 tions for the most part wherever 

 it has been carefully looked for. 

 It measures about inch in 

 length, and is dark grey above, 

 whitish below, and bears a pair of 

 eyes near the anterior extremity 

 (Fig. 15, B). Bijpalium kewe?ise 

 (Fig. 1 5, A), which has been found 

 in the forests of Upolu, Samoa, by 

 Mr. J. J. Lister, has been accident- 

 ally imported, from the (unknown) 

 districts where it is indigenous, 

 with plants and soil to various 

 parts of the world England, 

 Germany, the Cape, and also to 

 Sydney, where it appears to have 

 established itself. In these 



x A (after Bergendal) ; B, Rhyncho- ipalia living ill hothouses, the 

 ctciivus tcvTCstv'is F 1VI x 2 * C 



Geodesmus uiinecitus ' Metsch., x 2 genitalia never appear to attain 

 (after Metschnikoff). mr Region of matll rity, and apparently multiple 



mou tli ; gp, region of genital pore. . J ' rr J 



fission and subsequent reparation 

 of the missing parts is the only mode of reproduction. Geodesmus 

 bilineatus (Fig. 15, C), which has occurred at Giessen, Wiirzburg, 

 and Dresden, has, in all probability, been introduced with ferns 

 from the West or East Indies. Microfilaria humicola, described 

 by Vejdovsky from dunghills in Bohemia, is doubtfully indigenous. 

 In marked contrast with the poverty of the temperate zones 

 in Land Planarians, is the abundance and great variety of this 

 group in Southern Asia, South America, and especially in 

 Australasia, where the rich Land Planarian fauna has been care- 

 fully investigated by Spencer, Dendy, Fletcher, and others, in 



1 Shipley, Proc. Camb. Phil. Soc. vol. vii. pt. 4, 1891 (with literature). 



Fig. 15. Some Land Planarians found in 

 Europe. A, Bipalium kewense Mos. 





