28 ARKIV FÖR ZOOLOGI. BAND 3. N:0 28. 



gous to wliat we have found in the other two genera and the 

 »lacinise» seem to be as liighly developed as in these. 



Paramegistus is distinguished from Neomegistus and An- 

 tennomegistus through the male not having the sternal and 

 ventri-anal shield fused and in this respect agrees with Antenno- 

 phorus grandis. 



Finally Neomegistus and Antenno7negistus differ from each 

 other through the former having the epigynial and paragynial 

 shields fused with the ventri-anal shield along their base, where- 

 as in the latter they are demarcated from it. 



Although, upon the whole only a comparatively small 

 number of commensualistic Antenno'phorinm being known, it 

 may seem to early to venture upon the task of traceing 

 the phylogeny of them, I am nevertheless of the opinion, that 

 the find of the tritonymphse of Neomegistus enables us at least 

 to sketch the leading features of it. I äm not aware of any 

 other attempt having been made to trace the phylogeny of the 

 Antennophorinse than that of Berlese,^ Avho arranges the 

 »genera mesostigmatum secundum ordinem naturalem dispo- 

 sita». He derivates the genus Anten7iophorus from Lcelaps 

 through Neoherlesia and Megistanus from Antennophorus . This 

 attempt must be considered as a complete failure, as even if 

 Neoherlesia has biologically a position intermediate between 

 Lcelaps and Antennophorus and thus indicates in which way the 

 praedecessors of A. have assumed their commensualistic life, 

 this is no reason why N. should in other respects be a form 

 intermediate between the two. Furthermore Antennophorus 

 can naturally not be derived from a Lcelaptine, but only from 

 a form whose male has a similar position of the genital aperture 

 as ^. viz. in the sternal shield. Amongst the subfamilies, which 

 on account of a similar situation of the J^ genital aperture could 

 be taken into consideration, all, with exception of the Epicriince 

 {Zerconince) are too differentty shaped to invite discussion 



Amongst the Epicriince Berlese has placed a genus, Se- 

 jodes,^ which, however, according to the table of the subfamilies 

 which he gives himself does not belong to the subfamily in 

 question, because the (^ and $ chelae of Sejodes are provided 

 with appendages and it has well developed metapodial shields. 

 In this respect S. agrees ivith the Antennophorince. 



^ Acari, Myriapoda etc. Ordo Mesostigmata, p. 16. 

 '^ He oalls it an aberrant genus. 



