igig.] N. Annandale : Bouihay Streams Fauna. 113 



II. The Fauna of Mountain Streamlets at Khandai^la. 



The hills at Khandalla are fairly steep and almost bare or 

 at any rate devoid of heavy jungle. Numerous small streams 

 rush down them, falling over many cliffs and rocks and thus 

 forming cascades and waterfalls, some of which are of a con- 

 siderable, even a great height. The streams are for the most 

 part very small indeed, nowhere more than a yard or two across 

 and in the deepest pools not more than a foot or two deep. This 

 description applies to their conditions in the dry season ; in the 

 rainy season they must be small but raging torrents, the biologi- 

 cal investigation of which would be difficult. In the following 

 notes I discuss the true aquatic fauna of these streamlets ; the 

 fauna of damp rocks at the edge of the waterfalls will be con 

 sidered separately. 



It is impossible at present to give anything like a full account 

 of the fauna of any body of water in India, because it inevitably 

 includes among its members a large proportion of insect larvae 

 even the adults of which are imperfectly known, if known at all. 

 This is particularly unfortunate in the case of small torrents, the 

 insect larvae of which are almost without exception highly modified 

 and adapted forms. In present circumstances, however, it is 

 perhaps best to ignore the curious flattened Ephemerid and other 

 larvae that play an important part in the natural history of the 

 streamlets at Khandalla, and also the aquatic and semi-aquatic 

 beetles which, though never of large size, are by no means un- 

 common in the water or at the edge. Mr. Paiva's co-operation has 

 made more satisfactory reference to the Rhynchota possible. I 

 shall do no more than mention here that Anopheline larvae are 

 abundant in small pools and that the adults rest in large numbers on 

 damp rocks shaded from the sun and standing in the water. It 

 will be remembered that my observations were made in March, 

 when there was very little water in the streamlets. 



Batrachia. — The only frogs observed at the edge of the 

 streamlets were Rana limnocharis syhadrensis and Ixalus bomhayen- 

 sis , both of which were fairly common under stones. The Ixalus was 

 also found in the cracks between the narrow strata of the rocks 

 ovei which little cascades fall in the streamlets. These cracks 

 often make it possible to strip off slabs of stone by the exercise of 

 a little force, and when this is done the frogs appear flattened 

 against the parent rock, with their pupils strongly contracted. 

 With them there is abundant food, particularly in the form of 

 earwigs (Fom/)w/«), which greatly favour such situations. When 

 the streamlets become broader owing to natural or artificial ob- 

 structions in comparatively level areas Rana cyanophlyctis is abun- 

 dant round the margin. I found no tadpoles of any species. 



Fish. — Three species of fish, all very small, make their way 

 into the smallest pools in the streamlets. They are N emachilus 

 etezardi, Discognaihus nasutus and Psilorhynchus tentaculatus. 

 All of these, and especially the two last, are modified forms. 



