Oudemans, Notes on Äcari. 



401 



P a t r i a unknown ; see above sub H a b i t a t. 

 i F u n d by Dr. E. L. Trouessart ; see above sub H a b i t a t. 



Type in collection Trouessart. 



5. Trott essartia rosterii (Berlese). (Fig. 22.) 



In consequence of the discovery of an extremely narrow 

 canal in the hyaline membrane between the tail - pieces of the 

 bregoing species (see above p. 398) , I carefully examined my 

 own preparations and I discovered in three females of Tr. rosterii 

 (Berlese), which are provided with a minute „appendiculum", that 

 this appendiculum is a little 

 tube , through which goes 

 another tube. Following this 

 latter forwards , it proved to 

 be an evacuation tube of a 

 long spool - shaped bladder 

 (fig. 22) , which is situated 

 not far from the trochanter 

 of leg IV , in one individual 

 to the left , in another to 

 the right. 



What niay be the signi- 

 fication of this long tube and 

 bladder. I think the small 

 tube or „appendiculum" is com- 

 parable with the copulation- 

 tube of the female Glycyphaginae 

 and the bladder is a recepta- 

 culum seminis. I know very 

 well that the female does not 

 copulate ; nevertheless in the 

 female , after having cast its 



nubile - nymphal skin , this copulation - tube and the canal which 

 joins the tube with the receptaculum seminis evidently persist. 

 I confess that I could not discover a junction of this bladder 

 with the oviduct or ovary. 



Therefore it is also probable that this bladder has changed 

 its physiological function, has changed in a gland, the products 

 of which may serve to drive away ennemies (e. g. Cheletidae). 



There is another striking particularity in this species. Like 

 the foregoing one its hind-legs have only 4 joints instead of 5, 

 but here the reason of having a Joint less than usually is quite 

 another. We may at once observe in our drawing (fig. 22) 

 that here has place a junction of the tibia and tarsus, 



Fig. 22. Trouessartia rosterii (Berl.). $. 





