vi Preface 



Dr. Purcell was kind enough, at our reijuest, to send us that remarkable animal at 

 once, and we have described it below under the name of Purcellia illustrans, because amongst 

 all the animals belonging to this suborder, which we have examined, this one has been the 

 most instructive to us. Thanks to our having a fair number of specimens at our disposal, 

 we were able to obtain accurate knowledge of several structural features which are of im- 

 portance in this suborder. At the same time the distinguished Arachnologist, Mr. Eugene 

 Simon, presented us with a specimen of Cryptostevivia, the examination of which led to results 

 that seemed to throw more light on the hitherto little known order Ricinulei. Under these 

 circumstances we resolved to undertake as thorough an investigation of these groups as we 

 could, and for this purpose to bring together as much material as possible. This we considered 

 so much the more desirable, as most writers have hitherto placed Ricinulei amongst Opiliones. 

 Our ajDplications were met almost everywhere with the greatest readiness to help, material for 

 our investigation of these little-known groups of animals having been lent or even given 

 us by the gentlemen and instituti(_>ns named below, and we have accordingly much pleasure 

 in expressing our warmest thanks to Professor E. Ray Lankester and i\Ir R. I. Pocock of the 

 British Museum, the Rev. 0. P. Cambridge, Professor E. B. Poulton of Oxford, Dr. W. F. 

 Purcell, Prof Dr. Max Weber and Dr. J. C. C. Loman of Amsterdam, Mr. Eugene Simon 

 and Dr. G. Joseph of Paris, Dr. R. Gestro of the Museo Civico at Genoa, Prof Dr. C. Emery 

 of the Museum at Bologna, Dr. R. Sturany at Vienna, Prof Dr. K. Mobius and Prof. Dr. F. 

 Dahl of the Museum at Berlin, Prof Dr. Chr. Aurivillius of the Museum at Stockholm and 

 Prof Dr. T. Thorell. We are especially indebted to Mr. Eugene Simon for his kindness in 

 placing the whole of his excellent material at our disposal and even presenting us with 

 several duplicates, as well as with a series of ty]3es of various Palpatores. — We have also to 

 thank our friend C. C. A. Gosch, Mag. Sci., Attache at the Danish Legation in London, 

 for having translated our manuscript into English. 



Moreover, in no mean degree, our thanks are due to the Roj\al Society of London which 

 has done us the honour of accepting our paper for publication ; for this we are so much the 

 more grateful as it might have jjroved very difficult to get it published in our own country. 

 And we desire to add our acknowledgments to the Cambridge University Press for the very 

 admirable manner in which the illustrations have been rei)roduced and the text has been 

 printed, and for their attention and courtesy. 



Finally, we wish to express our warm thanks to the Rev. T. R. R. Stebbing, F.R.S., 

 for having communicated our treatise to the Royal Society and for his very valuable aid 

 in looking through all the proofs. 



H. J. H. W. S. 



June 15, 1904. 



