Introductory Remarks. 



Ti 



he observations, included in this paper, were chiefly made on material, 

 belonging to the Zoological Museum of Copenhagen, mostly collected by the 

 Danish Galathea and (he Danish Siam t^xpedition, respectively by the Entomologist 

 Mr. Kjellerup and the Zoologist Dr. Th. Mortensen, both able collectors. For the 

 kindness of letting me work out these collections I ask Dr. C. F. Meinert, the 

 curator of the Arthropods of this institution, as well as Dr. Th. Mortensen, who 

 made such good collections at the Siamese Island of Koh Chang, to receive my 

 best thanks. A good many of the observations, included in the general part, and 

 the descriptions of a few Indian species were made during a stay in London on 

 material, belonging to the British Museum (Natural History); for the liberality, 

 with which this collection was handed over to me, I tender to the Director Professor 

 E. Ray Lankester my best thanks once more. I feel also indebted to Professor 

 Sydney J. Hickson of Manchester, because he sent me four specimens of Ch. super- 

 bus n. sp., remarkable on account of the coxal sac of the male, and to Mr. Edv. 

 Ellingsen of Kragerö in Norway, because he kindly gave me the opportunity of 

 examining Feaella mirabilis EH., a most interesting form. 



As the present work was already finished, long before the above mentioned 

 animal was examined by me, I was not able to pay any attention to its most 

 astonishing structures in the general part of these investigations and refer you to 

 his paper on this subject (72., cf. also footnote under "Synopsis of families . . ."). 



A host of scientists have worked on the natural history of the Chelonethi, but 

 our knowledge is nevertheless rather incomplete. The authors, who have more than 

 any others promoted the systematic study of this group by giving good and concise 

 descriptions of the species are L. Kock and E. Simon, of the older generation and 

 L. Balzan more recently. Our knowledge of the inner anatomy is principally due 

 to A. Croneberg, and it was H. J. Hansen, who by his good observations as far as 

 the chitinous skeleton is concerned, laid the foundation of a natural classification. 

 The Bohemian Professor Ant. Nosek of Caslavi has recently done a useful work 

 by giving lists of the species of Chelonethi as well as of the papers, in which infor- 

 mation about these animals mav be found (cf. fiO — 62). 



