480 W. WILLIAMSON AND C. D. SOAR ON BRITISH HYDRACARINA : 



with Thor that he and Lebert had obtained the same species in 

 the restricted area. But in re-establishing the species, Sig Thor 

 overlooked the fact that it had been previously designated as 

 type, and consequently we find that the original genotype and 

 the type of the sub -genus to which the genotype belongs are not 

 the same species. Further we find that the sub-genus containing 

 the genotype bears a different name from the genus, but one feels 

 sure that the rules laid down for guidance in such cases by the 

 International Zoological Congresses have been overlooked by the 

 indefatigable Norwegian acarologist not by design, but purely by 

 accident. To this we shall revert later. 



A more troublesome matter, however, is the consideration of 

 two of Koch's species as members of the genus Lebertia, viz. 

 Hygrobates iconicus C. L. Koch, and H. inaequalis 0. L. Koch, 

 the former as a doubtful species, the latter as valid. These are 

 represented in Koch's Deutschlands Crustaceen, Myriapoden und 

 Arachniden in Heft 11-22/23 and Heft 11-20/21 respectively. 

 As Koch's work is not to be found in many of our libraries, it 

 will not be out of place to reproduce here Koch's descriptions of 

 the above species ; and as these can be taken as typical of the 

 descriptions in Koch's great work, workers who have not hitherto 

 had access to it will comprehend something of the difficulty 

 attending the identification of many of Koch's species, difficulties 

 which, moreover, are not rendered more easy of solution by his 

 figures of species. 



11. 22 foem., 23 mas. 



Hygrobates iconicus. 



H. subglobosus, Jlavus, nigro-pictus, pedibus ciliis nullis. 



Gross, fast kreisrund, doch ein wenig langer als breit, gewolbt, 

 glanzlos, zwei grosse Griibchen hinten an dem Mittelfleck, zwei 

 auf dem Riieken des Hinterleibs,. das Bruststiick vorn in zwei 

 Zahne verl'angert. Die Taster massig lang, ohne Auszeichnung. 

 Die Beine diinn, die vordern kurz, kaum so lang als die 

 Korperbreite, die hintern langer, alle kurzborstig, ohne 

 Schwimmhaare. 



Gelb, die Flecken braunschwarz oder schwarz : die Mittelfleck 

 kurz, fast von der Gestalt eines Quadrats ; die Seitenflecken bis 

 zum Auge ziehend, breit, nicht lang. Die Riickenstreifen mit 



