Oct. 9, 1884] 



NA TURE 



563 



from most of the rivers where formerly they had abounded, 

 and thousands were seen floating dead down the stream, 

 destroyed apparently by some species of Saprolegnia. It 

 is satisfactory to note that of introduced fish the colonists 

 have now a fine non-migratory trout (brown trout) and a 

 splendid sea-going migratory salmon, the exact species of 

 which is still involved in uncertainty. Among marine 

 fishes special mention is made of the Barracouta (Thyr- 

 sites atuii) and Kingfish ( 77/. solandri), which abound all 

 the year round ; but there would appear to be next to no 

 attempt to cure the fish for the foreign market. Mr. R. 

 Etheridge contributes a paper on Trilobites and other 

 fossils from the Lower Silurian rocks of the Mersey River 

 district, Tasmania. Several new species are described, 

 and the species of Trilobites and Brachiopods are figured. 

 Lieut. Beddome describes sixteen new species of Tas- 

 manian shells, and Messrs. Higgins and Petterd some 

 new species of Antechini and Muridae. 



The volume for 1883 contains 65 pages and but few 

 memoirs. Messrs. Higgins and Petterd describe in it 

 some new Tasmanian mice, and the same authors con- 

 tribute an interesting account of a new cave-inhabiting 

 spicier. This species [Theridion troglodytes) was found 

 in a recently-discovered cave in the Chudleigh district. 

 The cave was found to consist of several chambers, in the 

 innermost of which the spiders were found. The floor of 

 the cave is about thirty feet below the level of the present 

 entrance, and is only reached by two well-like descents of 

 from fourteen to sixteen feet each, connected by low pas- 

 sages. There was also found a large deposit of mamma- 

 lian remains, some in the crevices of the rocks, others 

 embedded in the earthy and stalagmitic floor. These 

 remains can be all referred to non-carnivorous marsupials 

 and mice. It is strange that no insects were found, but 

 the cave would seem to be worth a more detailed investi- 

 gation, which the authors promise, adding that the stalac- 

 tites surpassed in beauty those of the well-known 

 Chudleigh Caves. 



EXPLORA TIONS IN ICELAND 

 The Lava Desert of OdaSahraun 



IN about the central region of Iceland, on the northern 

 skirts of Vatnajokull, the largest glacier in Europe, 

 is situated the most extensive occidental lava desert, the 

 OdaSahraun, covering a total area of about 16,000 square 

 miles English. The whole of this wilderness is almost 

 entirely one barren mass of lava, though here and there 

 the traveller may observe patches filled with drifts of sand 

 giving growth to some few stray tufts of upright lyme- 

 grass (hfymus arenarius) ; but frequently a journey may 

 be made through this region for days together without 

 one single blade of grass being sighted. The total ab- 

 sence of vegetation and water in these tracts makes 

 travelling here excessively arduous and risky, and these 

 difficulties are still more aggravated by the elevation of 

 the country above the level of the sea, in consequence of 

 which it may frequently happen, even in the midst of 

 summer, that the traveller is enveloped in blinding snow- 

 storms, which preclude all attempts at further progress 

 while they last. In such predicaments no reliance 

 can be placed on the compass, because of iron enter- 

 ing so very largely into the composition of the lava- 

 masses. Hence this desert has hitherto remained a 

 terra incognita, and has never been surveyed ; yet volca- 

 noes of gigantic dimensions are found here, and many 

 natural phenomena beside, which command great scien- 

 tific interest. Not only to the world of science has 

 OdaSahraun been an unknown region, but even the in- 

 habitants of the surrounding country-side have at all 

 times entertained the most vague and ignorant ideas 

 concerning it. For ages they pictured it to themselves 

 as the home of trolls and mountain sprites. Even as 



late as the present century it was commonly believed that 

 up among the volcanoes there were to be found verdant 

 valleys containing a whole population of outlaws ; a belief 

 which took its rise and received its fortification from the 

 fact that jets of steam issuing from the crevassed moun- 

 tains were taken by distant beholders for smoke ascend- 

 ing from the chimneys of the abodes of outlaws. The 

 outlaws themselves were pictured to the imagination as 

 either human beings of a savage type, or as some preter- 

 human race of gigantic strength. So firmly ingrained in 

 the people was this belief, that even as late as 1830 an 

 armed expedition was despatched from Myvatn for the 

 purpose of exploring the haunts of these communities of 

 outlaws, the result of which, I need not say, proved 

 discouraging. 



In ancient times one of the highways of the country 

 ran across the northern portion of OdaSahraun, which 

 early records show the bishops of Skalholt to have been 

 in the habit of taking on their visitation tours to the east 

 country. This road was used for the last time in 1736, 

 but has been lost since, and now no one is able to point 

 out its locality and direction. Across the southern por- 

 tion of the lava no attempt at forcing a passage had ever 

 been made by man until a certain adventurer named 

 Pjetur Brynjulfsson, in 1794, succeeded in threading his 

 way from the East Fjords westward between the lava 

 and the northern spurs of Vatnajokull, until he struck 

 the road of Sprengisand, which traverses the country 

 right across from the northland to the southland quarter. 

 In 1S38 Bjorn Gunnlaugsson, the famous constructor of 

 the best map of Iceland, undertook a journey of explora- 

 tion to Odl<5ahraun, but fell in with such tempestuous 

 weather that all his attempts at exploration were defeated, 

 and he himself barely escaped with his life. Next year 

 he repeated his journey, and, being favoured with better 

 weather, he forced his way from the south up into the 

 boundary line between the lava and the glacier, and 

 pushed on some distance to the eastward. In this trip 

 he attained some positive results. In 1S40 a Danish 

 naturalist, Schythe, intending to explore this region, took 

 the same route, but was overtaken by such excessively 

 stormy weather that, after having lost most of his horses, 

 he just escaped with extreme difficulty into the country- 

 side of Jokuldal in the east country. From this time no 

 attempt at reconnoitring this wild country was hazarded 

 until the stupendous explosion from Askja in 1875 gave 

 such surprising evidence of the enormous activity of 

 the volcanoes in these wildernesses. This year Mr. 

 Watts made his way right across Vatnajtikul, striking 

 Askja in his descent over its northern spurs. Shortly 

 afterwards Askja was visited by an Icelander, Jon Thor- 

 kelsson, who made his way up to it on foot in the midst 

 of winter. In the summer of 1S76 the Danish Govern- 

 ment despatched Prof. Johnstrup with a party of scientific 

 men to these volcanic wastes, who explored the region of 

 Askja and constructed a map of the volcanoes. Prof. 

 Johnstrup's is the only scientific exploration that ever yet 

 was carried out in OdaSahraun. At more recent dates 

 Askja has been visited by several English tourists, such as 

 Messrs. Lock, Coles, and Morgan. In 1880 several far- 

 mers from the districts of Myvatn and BarSardal made 

 the complete circuit of OdaSahraun. But,_in spite of all 

 such reconnoitring trips, the whole of OdaSahraun is 

 practically unknown yet, with the exception of the corner 

 occupied by Askja. 



Instructed by the Government, I have now for several 

 years been engaged in surveying the upland tracts of Ice- 

 land, exploring the country geographically, and examining 

 into its geological structure and character generally,. This 

 summer I resolved to attempt an exploration of OdaSa- 

 hraun with such means as I had at my command. With 

 a view to more expeditiously effecting my purpose, I 

 adopted the plan of selecting certain fixed stations on 

 grassy spots here and there about the wildernesses which 



