(de. a. C. OÜDBMANS). NEW LIST OF DUTCH ACARI, II. 13 



6. Dermanyssus gallinae (de Geei). 

 (With Plate 1, fig. 2 and 3). 



My specimens are positively of this species ; and yet the ventral 

 side of the females does not correspond with the figure of Berlese 

 (Ac. Myr. Scorp. Ital. fase. 53, n°. 1 and n°. 4), nor with the 

 description : « scutum sternale tantum vitta transversa chitinea 

 significatum » (Berlese loc. cit. n^. 4), nor witn the passage in 

 the diagnose of the family Ber many ssiäae : « In ferne in ventre 

 scutum sternale perstriclum in quadam specie conspicitur, inter 

 secundi pares coxas, quasi viltà chitinea extensum. Scutum genitale 



abest, et vulva rima anterius dermate longitudinaliter striato 



inter pedes aperitur ». 



In my figure 2 it is clearly visible , that behind the so-called 

 sternal shield : « vitta transversa chitinea inter secundi paris coxas», 

 there is a very long space , reaching from this « sternal shield » to 

 nearly the middle of the « venter », which space is totally deprived 

 from the common very fine wrinkles that characterize the soft 

 skin 0Ï Dermani/ssus and allies. In this space , invariable in breadth 

 and length in different specimens , they may be fasting or well-fed, 

 distinctly three parts are visible, viz. 1. an unwrinkled one, rounded 

 anteriorly , concave posteriorly , and which I consider to be the 

 hinder part of the sternal shield , whilst the « vitta transversa 

 chitinea» of Berlese is the fore-part of the same shield; these 

 two parts are still separated by a îvrinkled space of skin ; 2. the 

 longitudinally folded skin between this shield and the genital 

 aperture ; 3. an oval shield , with the blunt top forwaid , reaching 

 from the genital aperture to nearly the middle of the « venter ». 

 This shield is a very genital one. 



Fig. 3 shows us the ventral side of the male. There is a distinct 

 sterni-genital and a ventri-anal shield , not , as is delineated and 

 described by Berlese, one unbroken sterni-geniti-ventri-anal shield , 



Curious is the fact, that Megnin mentions (Les parasites et les 

 maladies parasitaires, 1880, pag. 115) and delineates (Atlas PI. 1) 

 the sternal and genital shields , and that Berlese (1892) denies them ! 



