HYDRACARINA FROM STRATHEARN 89 



HYDRACARINA FROM STRATHEARN. 



By William Williamson, F.R.S.E. 



When in Comrie in August 191 5, I made a few collections 

 of Hydracarina in the neighbourhood. A visit to Drummond 

 Pond yielded : Fiona longiconiis iviniinuta (Piersig), ? ; 

 Lininesia fiilgida (C. L. Koch), <^ and ? ; L. maculata 

 (O. F. Miill.), ? ; L. uncMata (O. F. Miill.), $ ; Brachypoda 

 versicolor (O. F. Miill.), 9 and $\ ArrJienurus globator 

 (O. F. Miill.), ?; Frontipodci uuiscidus (O. F. Miill.), ?; and 

 Hygrobates longipalpis (Hermann), $ and $ . A roadside 

 pool on the way from Comrie to Glenartney yielded : Fiona 

 carnea C. L. Koch, c^ ; Arrheniiriis cylindratus, Piersig, 

 $ and ?; and A. candaius {Geer), S- I had hoped to get 

 good results from the pond close to Lawers House, but at 

 the time of my visit the water had been temporarily 

 drawn off. The proprietor of the estate (Rev. C. D. 

 Robertson Williamson), however, very courteously directed 

 me to some likely places on the estate. A hill tarn to the 

 north of Lawers House yielded only Diplodontus despiciens 

 (O. F. Miill.), of which a number of both sexes were taken 

 as well as one nymph. A tarn near the railway, though 

 apparently a much less likely place than the former, yielded 

 better results. Hygrobates longipalpis (Hermann), $ ^ $ , 

 and nymph ; H. nigroniaciilatus Lebert, immature ? ; and 

 Arrhejiurus cylindratus Piersig, $ , $ , and nymph, were 

 represented, as well as Atractides anonialus C. L. Koch, $. 

 The most noteworthy capture here proved to be Lebertia 

 angulata Sig Thor, not previously known to occur within 

 the Britannic area, and supposed to be limited to Norway. 

 The hitherto unknown nymph was also taken. 



Lebertia angulata Sig Thor, without its rather pronounced 

 antero-Iateral corners and the more weakly developed postero-lateral 

 ones, may be described as being nearly round in outline. The 

 dorsum is somewhat flattened, so that the body is not thick. The 

 skin is covered with fine, short, closely set, chitinous ridges, and 

 in colour ranges from a pale yellowish brown to a dark brown, 

 ^2 M 



