17^ The Irish NatJi7'alisi. vSeptember, 



All the Irish examples of this spriugtail are remarkable on 

 account of the elongation of the feelers, legs and spring. I 

 propose, therefore, to regard them as types of a distinct variety 

 {eltmgafa) of the species. In typical A. bidejiticulata from 

 Franz Josef Land, the relative lengths of head and trunk, 

 feelers, hind legs, and spring are as 15, 5, 5, 7. In the Irish 

 variety these lengths are as 15, 7, 6, 8. In colour, the Irish 

 specimens are a fine purple or green, with pale legs and 

 ^spring. Adults attain a length of 2*5 mm. 



Agfenia bidenticzclafa has a wide range in arctic and northern 

 regions. Schaeffer('oo, p. 247), enumerates records from Green- 

 land, Spitzbergen, Novaj-a Zemlya, Franz Josef Land, Cape 

 Chelyuskin (the extreme northern point of Siberia), and the 

 mountains of Scandinavia. He also states that /. lamcginosa 

 described b}' Carl ('99, pp. 307-310) from the Swiss Kngadine 

 (altitude 1250 m.), is identical with the present species. Agren 

 ('04) and Linnaniemi ('07), have since recorded^, bidcnticnlata 

 from Lapland. The presence of such a distinctively arctic 

 and alpine insect in these islands is therefore of exceptional 

 faunistic interest. Last year, after I had identified ni}^ 

 Waterford and Mourne specimens. I received examples of the 

 species from Mr. R. S. Bagnall, who had collected them under 

 stones in the Upper Tyne. Subsequentl}^ Mr. Bagnall sent 

 me specimens from streams in Arran and on the opposite 

 mainland of A3'rshire, while quite recently my friend Mr. W. 

 Evans of Edinburgh, has told me that he collected the species 

 some time ago near Callander. It is evident, therefore, that 

 this arctic vSpringtail has a wide distribution in the northern 

 part of Great Britain, as well as in Ireland. In structure the 

 British specimens are somewhat intermediate between the 

 typical arctic form and the Irish variety elongata. The habitat 

 of the species in Great Britain, is however, as in Ireland, 

 under partly submerged stones in hill streams. In its arctic 

 and alpine localities, the insect has been found in similar 

 situations. Carl ('99, p. 310) states that in the Engadine he 

 found tiie insect on the surface of the snow, into which the}' 

 burrowed to protect themselves from the sun's heat. We 

 sIujU probably be safe in including this interesting species 

 among the many remnants of glacial conditions that may be 

 found in our Irish uplands. 



