6 
Indiana University Studies 
stirs it to the bottom. In contrast to this the surrounding 
smaller lakes and lagoons are deep and the water straw- 
colored. The lake contains few species, but the nearby lagoons 
contain many. The fishes taken were swamp inhabiting forms 
typical to the Amazonian lowlands. 
The second side-trip was made by means of Indian carga- 
dores during December along the foothills of the Andes to 
Ixiamas and Tumupasa. This trip yielded several species com- 
mon to clear rocky streams. 
The rainy season which usually begins during October and 
is followed by a dry November held off until the first of 
January. Then three days of tropical downpour swelled the 
river until fishing was next to impossible. Stops made at 
Ivon and Cachuela Esperanza during February and March 
yielded few species. From Cachuela Esperanza the expedi- 
tion returned to New York via Manaos and Para. 
I wish to express my appreciation to Dr. H. H. Rusby for 
the privilege of accompanying the Mulford Expedition, and 
to Dr. C. H. Eigenmann, thru whom my appointment was 
made. I wish also to thank Dr. Eigenmann for his encour- 
agement and assistance while preparing this manuscript. 
Heretofore only a few species have been reported from the 
Beni basin. Perugia (“Ann. Mus. civ. storia nat. Genova, 
1897, ser. 2a, Vol. XVIII”) reported on the fishes collected 
by Professor Luigi Balzani in Bolivia. This collection num- 
bering about 200 specimens contained representatives of 37 
species, five of which were taken in the Mamore and 32 in 
the Beni and tributaries. Haseman collected a few species 
at Villa Bella at the junction of the Beni and Mamore rivers. 
They were collected at the beginning of the rainy season (Oc- 
tober 5, 1909). They have not been fully determined. The 
other collections have been very small, sometimes a single 
specimen finding its way into some museum. 
I collected about 6,500 specimens representing 155 species, 
of which 25 species, including four genera, were new. The 
first series of fishes is deposited in the collections of Indiana 
University. As far as possible duplicates are deposited in 
the Museum of the University of Michigan and in the Na- 
tional Museum. The first series of batrachians is deposited 
in the Museum of the University of Michigan. 
