126 (dr. a. c. oudemans) 



I have not observed any dorsal shield in this adult male , therefore 

 I am unable to tell anything about number and distribution of the 

 round spots and pores. The bristles between the stigmata and the 

 shield are much longer than in the nympha , and four of the hairs, 

 which stand near the hind-angle of the shield, too. It seems to 

 me that the adult animal is not frequent , being not necessary to the 

 preservation of the species , the nymphae being générantes , an 

 observation which is frequently made in Gamasids. 



13. Dermacarus arvicolae Duj. 



DujARDiN (Annales des Sciences naturelles, 3^ Série, Zoologie, 

 T. Xir, p. 249 and p. 264, tab. 11 , fig. 15, 16) badly describes 

 and figures a hypopus under the name of ilypopus arvicolae. Since 

 that dale, 1849, it seems that this animal is not found again, 

 at least not described and figured again and better. Mr. Poppe 

 procured me seven specimens of this species. 



In Das Tierreich, Sarcoptidae, this animal is placed in the genus 

 Berniacarm Haller, and I think rightly, for it has like the 

 hypopus 0Ï Berniacarus sclurmi/s (C ]j. Koch) petioled suckers under 

 the valvae of the fixing-apparatus. 



The animal's outline is oval , somewhat pointed in front, blunt 

 posteriosly. Its length is 0,325 mm. 



The dorsal surface (fig. 39) shows a distinct line between cé- 

 phalothorax and abdomen. The céphalothorax bears 6, the abdomen 

 10 very minute hairs. 



The ventral surface (fig. 40) shows two very small hairs near 

 the foremost margin , two palpiform tubercules at the spot where 

 the animal's mouth must be, the epimera of the first pair of legs, 

 forming an Y, the epiinera between the first and the second pairs 

 of legs, directed inward and hindward , but having between them 

 a space of their own length , the epimera before the third pair of 

 legs, bifui'cated at both their ends, the anus, with two valves, 

 each of thorn having two oblong suckers , three suckers behind 

 the anus, of which the middle one is oval and larger than the 



