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III. An Account of the South- American Cheliferinee in the Collections of the British 

 and Copenhagen Museums. By C. J. With.* 



Eeceived January 2, 1907 ; read April 23, 1907. 



[Plates XXIX.-XXXI. ; Text-figures 64-84.] 



At the suggestion of the Director of the British Museum, I have worked out the 

 collections of Chclonethi belonging to that institution ; this paper deals only with the 

 South-American part ; for showing me this confidence I ask Sir E. Kay Lankester to 

 accept my best thanks. I am also obliged to Dr. C. F. Meinert, the Curator of the 

 Arthropods of the Copenhagen Museum, for letting me work out its rich collections of 

 South- American Cheliferinm Sim., partly collected by Dr. Meinert himself in Venezuela. 

 I most heartily thank, too, Mr. Edw. EUingsen, of Kragero (Norway), for placing several 

 of his original specimens of South-American species at my disposal, as well as 

 Mr. A. S. Hirst, who was kind enough to assist me with the literature in several 

 ways. 



Copenhagen, !N"ovember 1906. 



GENERAL EEMAEKS. 



The author who has done more than any other to advance the study of the 

 CheliferioKM from South America is L. Balzan. His researches have converted this 

 region from practically " terra nuda " to one of the best-explored continents with 

 respect to the grjup in question. Later E. EUingsen published a number of papers 

 describing imperfectly known and new species. He has also done much to increase 

 our knowledge of the geographical distribution of these animals, and by practical 

 analytical keys has made the study and determination of the species a fairly easy task. 

 As the collection at my disposal was very rich (at least 300 specimens, comprising 

 36 species, of which 13 were new — about 45 species having been previously described), 

 and included a large percentage of the known species, as well as several new ones, 

 and as I found that important groups of organs were scarcely mentioned in the 

 somewhat imperfect descriptions given in Balzan's earlier papers, I thought it would 

 be very useful to work out a kind of monograph. The richness of the material 

 also made it possible for me to define more sharply than in a recently published paper 

 the limits of the systematic groups, most of which in future will probably be recognised 

 as natural genera f . 



* Communicated by Dr. W. T. Calman, E.Z.S. 



t To two papers of Alb. TuUgren (23-24), in which he deals with South- American Chelonethi, I have not 

 been able to pay due attention because they were published during the printing of this paper. 



VOL. sviii. — PART III. No. 1. — October, 1908. 2h 



