THE ANNALS 



AND 



xMAGAZINE OF NATURAL HISTORY. 



[SIXTH SERIES.] 

 No. 63. MARCH 1893. 



XXIX. — The Affinities and Origin of the Tardigrada. 

 By Prof. J. von Kennel *. 



Like the majority of the so-called aberrant groups in the 

 Animal Kingdom the Tardigrada have met with the most 

 diversified experiences in systems of classification. At one 

 time they were ranked among the *' Worms," at another 

 among the Arthropods, and they have been assigned at diffe- 

 rent periods both to Crustacea and Tracheata. They were 

 treated as an " appendage " to these groups or else as 

 " ancestors " of them, and were regarded as degenerate or 

 greatly reduced or as highly primitive forms. A comparison 

 of the various views upon this question has been furnished by 

 Plate t, who also discusses in a subsequent paper \ a theory 

 by Biitschli § which had previously escaped his notice. 



Now I am in entire agreement with Plate's view that the 

 Tardigrada can be brought into relationship only with the 

 tracheate Arthropods, and do not consider it necessary to 

 support or amplify the arguments which he advances against 



* Translated from the ' Sitzungsbericlite der Naturforscher-Gesellschaft 

 bei der Universitat Dorpat,' ix. Bd. Heftiii. (Dorpat, 1892), pp. 504-512. 



t Plate, " Zur Naturgeschichte der Tardigraden," Zool. .Tahrb. Bd. iii. 



X Plate, " Die Rotatorienfauna des bottnischen Meerbusens &c.," 

 Zeitschr. f. wiss. Zool. Bd. xlix. 



§ O. Biitschli, " Untersuchungen iiber freilebende Nematoden und die 

 Gattung Chatonotus,'^ Zeitschr. f. wiss. Zool. Bd. xxvi. 



Ann. & Mag. N. Hist. Ser. 6. Vol. xi. 15 



