54 MEMOIRS OF THE CARNEGIE MUSEUM 



itself here under rocks, and we placed the poison above the point where it runs into 

 the rocks. The branch was entirely too large to enable us to kill the fishes, but 

 the poison drove them out from under the rocks so dazed that we could pick them 

 up with our dip-nets. 



In all we took forty-two species, of which five were not found elsewhere : 1. 

 Brachyglanis frenata, 2. Brachyglanis phalacra, 3. Hemicetopsis minutus, 4. Pseud- 

 ancistrus nigrescens, 5. Characidium laterale. All of these were new. 



Here I also secured a series of related little catfishes that were either confined 

 to, or most abundant in, the cataracts of the lower Potaro. These are Brachyglanis 

 frenata and phalacra, mentioned above; Myoglanis potaroensis and Chasmocranus 

 longior and brevior. Other Pimelodince, Doradince, and Auchenipterince were ab- 

 sent. Lithoxus, a little loricariid catfish, was very abundant. It is flat and clings 

 to the rock, which is greatly resembles. They were especially abundant in rather 

 deep pools and could only be seen when the poison brought them fluttering to the 

 surface. Loricaria was not observed. Deuterodon pinnatus and potaroensis were 

 also abundant in the cataract, and Poecilurichthys abramoides and Mquidens potaroen- 

 sis occurred in a shallow pool near the margin. 



Tetragonopterine characins were scarce, but one representative of the Ser- 

 rasalmince was taken. Of the Characince there were none. The peculiar Sternar- 

 chorhynchus oxyrhynchus, Porotergus gymnotus, and Sternarchus leptorhynchus were 

 seen here for the first time. They were among the rocks and were driven out by the 

 hiari. The following letter preserves the impressions of this region in their freshness : 



Kangaruma, October 30, 1908. 



" I think I have written everybody and answered all questions, which need answering, so I may 

 continue my record. 



"I awoke before five, and as some of the Indians were stirring I began to sing "balahoo," re- 

 peating the word to an old college tune. It has been the reveille and march for the crew ever since 

 we first reached the Kaieteur. I learned several tricks yesterday in poisoning Waratuk that I 

 proposed to put in execution today at Amatuk. We first tried poisoning a little branch above the 

 fall at Amatuk, and got some things. Then we tried a more ambitious scheme of poisoning a 

 big branch below the fall. I found that the poison will drive some fishes out before it kills. We 

 had three men pound hiari and wash it into the branch of the northern part of the fall. William 

 and another Indian stood a long distance below after the water had flowed among and under rocks. 

 I at first stayed near a pool where they were poisoning. Soon Plecostomince began to come up. 

 They were new to me and I dipped with enthusiasm until I fell in. This broke the ice for me, for 

 I then waded from rock to rock, securing eighty-seven specimens of the new genus Lithoxus. William 

 came with a dip-net full of fishes, among them long curved-snouted Gymnotidce I had not seen. 



"We poisoned and waded, gathering in all half a bucketful of small fishes, all valuable as speci- 

 mens. It was rare sport, and I did not realize that it was ten o'clock and that I was played out. 



