522 IV AR TRÂGARDH 



in every instance necessary condensed the descriptions into 

 diagnoses. 



With regard to the nomenclature I hâve adopted the term 

 gnathosoma, established by E. Reuter (1910) for the so- 

 called « capituhim ». I hâve, however, retained the terms man- 

 dibles, palpi and hypostoma for practical reasons, although 

 I am convinced that they are homologuons with the cheliceres 

 and pedipalpi of other Arachnides, the hypostoma 

 being constituted by the fusion of the coxae of the maxillae. 

 OuDEMANs has tried to prove in the m audible s of an Uropoda 

 (1906, p. 638) the présence of six joints as in the legs, and has 

 accordingly homologizeddigitus fixus with genu- tibia, and 

 digitus mobilis with tarsus. He may be right in doing so; 

 in my opinion the mandibles of the Uropodinaeshow secon- 

 dary adaptations with regard to the prolongation of the basai 

 portion, and it is not impossible that the articulation obser- 

 ved by Oudemans is a secondary characteristic. For this 

 reason I hâve retained the usual terms for the mandibles, and 

 for the hair to be found at the base of upper jaw employed the 

 neutral term « pilus b a sali s ». 



In describing the différent organs, sucli as mandibles, 

 palpi, legs and others, I hâve applied the words « length, 

 width, etc. » to them as being regarded on latéral view when 

 mounted as microscopical préparations ; thus, the width of 

 the chela or the joint of a leg is the distance from the upper 

 to the lower edge of it ; the expressions « forwards, backwards, 

 upwards, etc., » on the other hand, always apply to the organs 

 when (( in situ ». 



In order to abreviate the expressions, I use lower terminal 

 tooth for the terminal tooth of the lower jaw etc. 



