295 



24. Liponyssus clielophorus Oudms., nov. sp. 



(With Plate IX, fig. 27—29). 



The name Leiognathus was chosen by Canestrini as the chelae 

 of these auirnals have no teeth. Therefore it is very remarkable 

 that one of the species has chelae with teeth. It is the best proof, 

 that these animals desceud from animals with chelae with teeth. 



I have two nytnphae, fouud by Mr. S. A. Poppe iu a nest of 

 Mus minutus, 28 Aug. 1896, in Vegesack. 



The nymphae resemble so strikingly those of Liponyssus muscull 

 (C. L. Koch), that it was at first riot easy to observe the differ- 

 eüces. Yet there are many. 



In the first instance the chelae (Fig. 29). These are distinctly 

 toothed ; both fingers with three cnsps; the first of the movable 

 one passes the first of the fixed finger. A distinct sense-organ 

 on the fixed one is present too. 



Further the scaly dorsal shields (Fig. 27). There are two large 

 and six smaller ones, whilst that of Liponyssus musculi (C. L. 

 Koch) shows two large and only 4 smaller ones. Both are longer 

 than in Liponyssus musculi, so that the anterior shield reaches 

 more backward and the posterior one more foreward here ; there- 

 fore the space between the two shields is relatively narrower here. 

 The two smaller shields ot musculi correspond with the most 

 anterior two of chelophorus. The rest of the dorsal surface is 

 striated, like in otber species. 



The sternal shield (Fig. 28) is subpentagonal, wide, poiuted 

 posteriorly ; this point does not reach the level of the centres of 

 the foveae 4. The anal shield small, remote from the sternal 

 nearly the length of this latter shield. Before the anal shield 

 only six hairs, whilst L. musculi has 4 pairs between the anal 

 and sternal shields. 



The epistoma is reaching far more forward, blade-like, auteri- 

 orly with an incision in the middle (Fig. 27). 



The hypostoma does not show the transparent distal appendages 

 on the horns, like in L. musculi. 



