A. C. OÜDEMAXS, NOTES ON ACARI. 87 



('/h'lrf.opsis iiiliabitiiio; (jiiills unv;iri;il)ly ure sleudertîv iluui tliose 

 ()]) St/ri/if/ophlliis. 'J'he aii)biil;ic.r;i of" both are alniost of the 

 •same construction, because l)otli ar(> ('Iwletiddt'. Most probably 

 the tarsus of tlie palps has n o t vanished but has united 

 with the tibia so tiiat the present last joint nuist be reo-ar- 

 ded as a t i b i o t a r s a 1 e; the femur and j^enu of the palps 

 have also a tendency to form a femorogenu. 



11. That C/i('letop.-:tis numeri does not ])r'dy ou Shniujop/iilus is 

 probably because it recognizes the relationshij) to it, but these 

 tender feelings change into voracity as soon as the creature 

 starves. On placing two C7/«^;^o/;.s/,s' //rV/vi^r/ in a cell together with 

 numerous I'l/roj/h/p/nts, you will observe that they never attack 

 each other as long as there is still any Tyroglijphu.^, but a 

 day after the last Tyroplyphini is sucked out they attack each 

 other. (It is known th it a l)/ro(ilypJnis is immediately killed 

 when a little quantity of spittle of the Chcletes has flowed 

 into the body of the former, whilst a Clieletes is immune 

 to this poison and moves its legs as long as still any blood 

 is in the body). 



Well, I believe I have memorated all what hitherto has 

 been written about parthenogenesis in Acari, and I believe to 

 have shown sufficiently that parthenogenesis hitherto is proved 

 only in one species: Cheletes eriulitus (Schrank), suppose 

 that Beck has not been deceived^). 



6. On the Suckerplate of the hypopi of 

 Tyroglyphidae. 



As is well known Michael considers the split before the 

 suckerplate of the hypopi of Tyroghjphidae as the anus, 



') U Deo. 1904. (three months after the closing of this essay). I just received 

 a lettre of Mr. Trouessart in which he writes: «Je suis heureux de voir que 

 vous avez ))ii reconnaître et distiùj^uer les adultes ç? et Ç de Syrmnophihis). 

 Ainsi tombe l'hypothèse ([ue j'avais emise autrefois sur les rapports de Syriti' 

 gophilus et de Chelatopsis." 



