1968] 
lilies — Wingless Stonefly 
33 1 
Patagonian experiences with the respective representatives of this 
life-type). As my own efforts in Mt. Kosciusko and on several 
Victorian peaks did not result in finding wingless stoneflies and as 
the activities of very able and effective collectors like E. Riek and 
A. Neboiss in suitable places during recent years did not succeed in 
such findings, the Mt. Donna Buang locality must be considered 
especially propitious for the evolution and persistence of such a 
species. The fair quantity of specimens collected by P. J. Darlington 
at this place did not include larvae, so the question of their aquatic 
or semi-terrestrial life must remain unsettled. Compared with the 
similar climatic circumstances in the occurrence of wingless species 
in the closely related genus Apteryoperla one should expect, how- 
ever, that the larvae of L. darlingtoni nov. spec, are not obligatorily 
water-bound, and could be obtained in company of the adults at a 
certain distance from fluid water. 
Gripopterygid larvae of many genera are specially adapted to the 
extreme conditions of life in very high elevation, above the timber- 
line and in melting glacier water. They are normally the uppermost 
colonists in high alpine creeks of the Notogea and Neogea, and 
exceed by far the ability of other families of Plecoptera to withstand 
these conditions. The very high oxygen content of extremely cold 
water together with the remote metabolic rate of oxygen consumption 
at low temperature, causes in many members of this family a marked 
reduction in the importance of the abdominal gills for respiration; 
the gill tuft becomes sparse and may even be completely lacking as 
in the Andean genus Notoperla. The respiration activity has shifted 
to the abdominal body wall. Larvae of this genus, therefore, obtain 
a certain ability to breathe outside the water in a humid atmosphere 
(they normally survive for several days if kept in moist moss). 
The high exposed places of their occurrence, especially melting 
glacier water, are very poor for the obtaining of nutriment; only 
little algae vegetation being available. There must consequently be 
an urge to search for food out of the water in the moist atmosphere 
on the vegetation of the banks and within the low grass and under 
nearby stones. Thus the ability to leave the water in the larval stage 
may be the reason for these high-mountain dwellers to spread into 
the neighboring humid terrestrial biotopes. 
The phenomenon of evolution of brachypterous populations at such 
places is reported for Plecoptera of all families and from all con- 
tinents, e.g., from Scandinavia by Brinck 1949. Parallel urge of 
winglessness as adaptation on wind-selection at exposed places and 
terrestrial life as adaptation against poor alimentary situation within 
