Scottish National Antarctic Expedition. "Scotia" Collections. Oollembola from 

 the South Orkney Islands. By George H. Carpenter, B.Sc., M.R.I. A., Professor 

 of Zoology in the Royal College of Science, Dublin. (With Plate.) Com- 

 municated by WILLIAM EVANS, Esq. 



(Read March 5, 1906.) 



INTRODUCTORY. 



Our knowledge of Antarctic Aptera has been growing rapidly during the last few 

 years, a number of species from remote southern regions having been described by 

 WILLEM (1902) from the countries south of Patagonia explored by the Belgica, by 

 SCHAEFFER (1897) from Tierra del Fuego, by ENDERLEIN (1903) from Kerguelen, and a 

 single Isotoma by the present writer (1902) from South Victoria Land.* We find in 

 the Antarctic, as in the Arctic regions, that in our advance towards the most remote and 

 inhospitable lands, where winged insects cease to be represented, the primitive Aptera 

 are still found fairly numerous in species, and often multitudinous in individuals. A 

 careful study of these small, frail insects fully repays the naturalist, both on account of 

 the interest of their structure and the light which their distribution throws on 

 geographical problems. For the wingless primitively wingless, as we believe 

 condition of these insects, their frail integument, and their concealed mode of 

 life make it highly unlikely that they can cross broad tracts of sea ; therefore 

 the presence of identical or closely allied species on widely separated islands or 

 continents may safely be regarded as sure evidence of the antiquity of the insects, 

 and of the former existence of land-connections to explain their present discon- 

 tinuous range. 



Three species of Aptera are represented in the collections from the South Orkneys. 

 All belong to the Collembola, and all are referable to the family Entomobryidse and to 

 the sub-family Isotominae, two being members of the cosmopolitan genus Isotoma, and 

 the third being referable to WILLEM'S recently described Antarctic genus Cryptopygus. 

 The two species of Isotoma indicate, as will be seen, affinities of the apterous fauna 

 of the South Orkneys to that of other Antarctic lands eastwards and westwards, as 

 well as to that of the Arctic regions, and even to that of the land whence the 

 Scotia sailed. 



Two of the species are so abundantly represented that a study of the jaws has been 

 possible. In this research much help has been gathered from the recent careful paper 

 by FOLSOM (1899) on the mouth- parts of Orchesella. 



* While this paper is passing through the press, WAHLGREN'S memoir (1906) on the Collembola of the Swedish 

 South Polar Expedition appears. 



(REPRINTED FROM THE PROCEEDINGS OF THE ROYAL SOCIETY OF EDINBURGH, VOL. xxvi., PP. 473-483.) 



