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NATURAL HISTORY. 245 
species which, from their great concavity of forehead, 
appeared to be C. marginatus. I also once saw, near 
Bolobo, the half-decayed head of an African gavial with 
a narrow snout, possibly Jecistops Bennettir. 
Land tortoises are rarely seen on the Congo; but a 
curious aquatic species of Zrionyx, possibly 7. niloticus 
(the so-called soft turtle), is commonly found. This isa 
very curious tortoise, possessing a droll probiscis, which 
has rather a perky turned-up look. _When the animal is. 
in the water he generally sinks entirely below the surface, 
leaving only his nostrils, at the end of this probiscis, 
above the water; thus he may remain concealed for a 
long time ready to pounce on his victims, which may 
either be insects flying low over the water, small aquatic 
birds, or even, they say, young crocodiles emerging from 
the egg. I had one of these curious creatures given me 
once by a native on the-Upper river, and I kept it in cap- 
tivity during several months, until it became quite tame, 
and distinctly increased in size, for when I first received it 
it was only four inches in length. It fed on worms and 
decaying meat, and throve so well that I fully hoped to 
bring it back with me to Europe, and had, indeed, started 
with the trionyx on my homeward journey. One day, 
however, he had disappeared from my canoe, and, on 
making inquiries among the men, I found to my. horror 
that one of the krumen, impelled by some unnatural burst 
of hunger, had roasted and eaten him! Not even the 
hearty “whacking” I gave the delinquent could console 
me for the loss of this interesting creature. 
The fine monitor lizards are well represented on the 
Congo. Apparently the two principal species are Monitor 
niloticus and M. albogularis. This latter is a really hand- 
some creature, brightly pied with dark-brown and white, 
and is often six feet in length when adult. The young 
specimens appear to be much brighter in colour than the 
adults, the white spots being yellowish and the brown 
markings greenish black. They are often captured by the 
natives, despite their ferocity, and brought for sale. Even 
when quite young they require to be fed on live fowls. 
