A. C. OUDEMANS. NOTKS ON ACARI. 81 



and the projecting end of the until valves. Tiie hole therefore 

 is extremely difficult to discern, but I have found it and have 

 even been able to trace the tube which leads from the hole 

 to the receptaculum serainis, of course not in a skin, but in 

 an entire creature; the tube is very short, much shorter than 

 in ^iirinijohin calceata (vi^here it is long and lies in windings). 

 I have already communicated in the Entoraologische Berichten 

 (v. 1, p. 164, 1 July 1904) my discovery that this recep- 

 taculum seminis, the tube and the hole persist in the adult 

 females. I am in the opportunity to assert that also in the 

 adult feujale of my Plutarchusia (the anomalous ferrale of 

 Sijringobia chelopxs sensu Trouessarti) 1 have been able to 

 discern the ventral hole, the tube and the receptaculum seminis ! 



I think I have settled now the question. There is in 

 Sì/riìi(johia chelopus but on e series of stages: larva, protonympha, 

 deutonympha and adult (male and female). — There is but one 

 kind of male, a heteromorphous one, so-called because it has 

 its 4''' pair of legs much thicker than in the, female and 

 curved medialward to form a pair of claspers in order to hold 

 the female in copulation — though this male is met with in 

 at least twelve different lengths of body and dimensions of 

 thickened legs IV. — There is no parthenogenesis 

 at all - - at least hitherto it is not proved by breeding. — 

 The so called homoeomorphous male belongs to the so-called 

 parthenogenetic female. — The so called parthenogenetic 

 deutonympha is well provided with a copulation bole and 

 therefore fully apt to receive the male. — The whole 

 anomalous series is another species — nay even belongs 

 to another genus. ^ 



What must we believe of the other obser- 

 vations of two kinds of males belonging 

 to one femaleV spread in literature of 

 Acari? 



I believe that the phrase in Das Tierreich, D e m o- 

 Tijdschr. v. Entom. LI. 6 



