400 B. A. Wray— 



caves are cut in the massive Upper Cretaceous limestones, and the 

 river Poik flows underground, where it passes from the more 

 arenaceous Lower Tertiary rocks on to the highly jointed and 

 massive Cretaceous dolomites and limestones. Where it emerges 

 at Planina as the Unz it is brought to the surface by the discordant 

 junction of these limestones with the underlying Triassic rocks. 

 The river Unz, after a very brief career at the surface, is again lost 

 to view to the south of Longatico (Loitsch) and ultimately reappears 

 at the surface at Verhnika (Oberlaibach), where it assumes its final 

 name. 



The river Reka, in the hinterland of Trieste, furnishes another 

 striking instance of subterranean drainage. For 50 miles it flows 

 in a north-westerly direction towards Trieste, following a shallow 

 synclinal fold of Flysch sandstones, but as soon as it flows over the 

 Cretaceous limestones it forms a series of deep sinuous gorges. 

 At St. Kanzian it suddenly disappears under the surface of the 

 plateau, passing tinder a massive wall of limestone over 500 feet high, 

 above which the village is situate. From thence it passes through 

 three immense grottos, connected by ponors (or funnel-shaped 

 channels), and eventually emerges as the river Timava, after a 

 subterranean course of over 18 miles. The Timava river (the source 

 of which has been immortalized by Virgil) is H miles long, and comes 

 to the surface as a powerful stream at the foot of a prominent lime- 

 stone scarp at San Giovanni, 15 miles north of Trieste. 



One of the most striking instances of underground drainage in 

 Herzegovina is furnished by the Ombla river, which emerges from 

 an underground channel, 3 miles north-east of Ragusa, after draining 

 the Popovo polje, and following an underground course of over 

 8 miles. 



In Montenegro, where subterranean drainage is a very common 

 feature, two of the most striking instances are furnished by 

 the Zeta and Crnojevitsa rivers. The former flows along the floor 

 of two or more poljes, and on its uneven floor between Nitchitchi 

 and Danilovgrad a mass of Cretaceous limestone occurs, through 

 which the river Zeta, after draining the Nitchitchi polje, has cut 

 an underground channel 6 miles long. It eventually reappears at 

 the surface at Povija, close to Ostrog, and to the immediate north 

 of Danilovgrad. The Crnojevitsa river, on the other hand,- makes 

 a sudden mysterious appearance from a huge unexplored cavern 

 at Rijeka, and after a swampy course of 3 miles enters Lake Scutari. 

 It is not improbable that this river may be the outlet of the drainage 

 of the Cettinje polje or basin. 



Caverns. 



Owing to its extensive system of underground drainage, the 

 lUyrian karst is celebrated for its caverns, the most famous of which 

 are those of Adelsberg, 50 miles east of Trieste, which are over 6 miles 

 in length. The major portions of the large grottoes at Adelsberg 



