590 BRITISH ORIBATTDJi:. 



a treatise on the Italian species Nicoletia corimta, in 

 which he called the genus Nicolctiella* 



In 1883 Prof. JBerlese called the genus Lahidostoma, 

 Kramer, and immediately under it printed the species 

 as Nicoletiella liUea.f 



As Berlese, in his ' Acarorum Sjstematis Speci- 

 men,' has abandoned both these names and calls the 

 genus Panoplia, I imagine that he considers that he 

 has means of identifying Canestrini's N. cornuta with 

 the Acarus denticulatus of Schrank and Linna3us. 



In 1882 Haller classed the creature at the end of the 

 OribatidtE, but inserted an explanation for doing so by 

 stating that it is probably more like that family than 

 like any other.^ 



I confess it seems to me that transferring the genus 

 from the Gamasidce to the OribatidcB is goino- from 

 one error to another, as it is even less like the latter 

 than the former family. The first pair of legs in the 

 OrihatidcB are invariably true walking organs like the 

 others ; in Nicoletia (or Nicoletiella) they are tactile 

 organs, as in Gheijletus, most Gamasidoi, &c., and are 

 not used as legs. All known Orihatidoi have five joints 

 to the leg, Nicoletia has seven. All known Oribatida3 

 have the same number of claws to each leg, and the 

 number is always one or three ;§ Nicoletia has a didac- 

 tyle claw on the first leg and tridactyle on the others. 

 Moreover, the style of claw is not similar. The respi- 

 ratory system in Nicoletia is entirely different from 

 that of the Orihatidce, the mandibles are not contained 

 in the camerastomum, as is invariably the case in the 

 Oribatidce, but are external organs, more like the Cheli- 

 cerse of Chelifers. Nicoletia is a swift, active creature, 

 apparently predatory ; the Oribatidce are slow, and all 



* " Osservazioni sulla Nicoletiella cornuta," ' Atti Soc. Ven. Ti-ent. 

 di Sci. Nat.,' vol. viii, fasc. 1. 



t ' Acarofauna Sicnla,' p. 9. 



X ' Beitrag zur Kenntniss dei* Milbenfauna Wuvttembei-gs.' 



§ Canestrini says that Nothrus sylvestris has didactyle c[aws, but I 

 think it is an error ; and, even if it were correct his description would 

 only amount to saying that the small claw is abortive on one side (see 

 the description of Nothrus sylvestris in this book, p. 490). 



