26 MR. G. A. BOULENGER ON A COLLECTION 
deep. Scales 42 in a longitudinal line, 11 in a transverse line. Silvery, with a darker 
lateral stripe; dorsal and anal with greyish horizontal streaks. 
Total length 80 millim. 
A single specimen from Mbity Rocks. 
POLYPTERID2. 
35. POLYPTERUS BICHIR Geoffr. (2). 
Mr. Moore informs me that a Polypterus occurs in moderate abundance in the lake, 
and although he did not bring home specimens, he feels tolerably confident, from his 
recollection of them, that the fish belongs to the typical P. bichir, which occurs in 
the Nile, the Niger, and the Congo, and not to any of the closely-allied species that are 
often confounded with it. 
APPENDIX. By J. E. S. Moors. 
In the foregoing description of the fishes which I succeeded in bringing through 
from Tanganyika to the coast, Mr. Boulenger has already alluded to the difficulties 
that were experienced in transporting them in spirit, through several hundred miles 
of often trackless, always scorching, forest, and of the inevitable losses which this 
entailed. ‘The difficulties of transport, however, were by no means all. It must be 
nearly impossible for anyone who has not visited the African lakes to realize their 
huge size and oceanic character. 
One must be as heavily equipped for dredging in these waters as would be required 
for effective operations in the open sea. It will easily be understood, therefore, how 
incomplete our knowledge of the deep-water fauna of these lakes must be considered, 
when it is remembered that on Tanganyika I was of necessity forced to work with 
native dug-out boats, and with nothing better than the natives themselves as motive 
power. 
In the case of the fishes, moreover, there are no sources of collateral evidence from 
which we may obtain any insight into the nature of the deep-water forms, for dead 
fishes, unlike molluscs, leave no shells behind them, to be thrown upon the beaches of 
the lake, whereby, in the case of the molluscs, we gain some knowledge of the 
existence of forms which have not been seen alive; nor can we make use of the 
knowledge of the inhabitants in this matter, for the best of the Tanganyika natives 
are but wretched fishermen, merely using either surface traps, or light and inefficient 
drag-nets, which are thrown out a short distance from the shore and then hauled in 
to the land. Such nets are necessarily used only on smooth sandy beaches, and 
consequently the fishes caught in them are only of those s:ecies which inhabit places 
