216 A. GUNTHER ON SOME RARE REPTILES 
If we are allowed to make a conjecture as to the principal food of the Matamata, we 
should be inclined to find it in small fishes, and especially tadpoles. These may be 
allured to the animal by the waving fringes of its neck and head, and could be 
readily seized in its feeble jaws, which would be equally ill adapted for cutting off 
plants or for holding a larger and stronger prey. 
Although no good figure of the Matamata has been published, the descriptions are 
sufficiently detailed to render another description unnecessary. However, there are 
two points which deserve special notice. 
Strauch (Chelonolog. Stud. p. 172) has already stated that athe give different 
accounts of the extent of the gular plate. In fact, in some specimens the gular plate 
is short, triangular, and bordered entirely by the postgulars, which form a broad suture 
together. In other specimens the gular plate is oblong, elongate, reaching the pec- 
torals, and entirely separating the postgulars. This lesser or greater development does 
not depend on age, as both forms of the gular are found in yery young specimens 
preserved in spirits in the British Museum. Unfortunately the origin of the majority 
of the specimens which I haye had the opportunity of observing is unknown; but 
such scanty information as I have been able to collect would have led me to the 
conclusion that the form with the short gular is peculiar to Guiana, and the other 
form indigenous in the system of the Amazons. In that case the name of Chelys 
Jimbriata would haye to be restricted to the former, and that of Chelys matamata to 
the Amazonian race, so named and figured by Spix. However, the two specimens 
living at the present moment (November 1880) in the Society’s Gardens, which were 
acquired at the same time and from the same source, show both modifications, and 
therefore make me hesitate to see in this remarkable difference more than individual 
variation. Its explanation as a secondary sexual character would be difficult to 
understand, and open to objection’. 
The second point to which I would draw attention is the coloration of the young. 
The shell and soft parts of the adult are almost entirely of a uniform brownish-red 
colour, resembling that of river-sand. Only on the neck faint outlines mark the 
position of the spots which are so conspicuous in the young. Specimens preserved 
dry become darker, brownish-black. The ground-colour of a young individual, the 
shell of which is 3 inches long, is light reddish, as in the adult, but the areola of each 
costal scute bears a large black spot; a brown line commences on the occiput, and is 
continued along the vertebral line to the caudal scute ; two brown raised ridges diverge 
from the frontal region towards each side of the occiput. ‘The lower part of the pro- 
jecting snout is deep brown. The throat is ornamented with four broad brown longi- 
tudinal bars, the two middle occupy the lower side of the throat, and are confluent 
near the chin, the outer are broader, and run from the angle of the mouth over the 
' Since these lines were written, the Zoological Society received two other examples, in one of which the 
development of the gular plate is intermediate between the extreme forms described, 
