199 
with minute scattered black dots and line; sternum narrow, con- 
tracted at each end, and with straight sides behind, rather truncated 
in front and more distinctly and broadly so behind. 
Hab. North America. 
There are several specimens of the first species of different ages, 
from various parts of the States, in the British Museum; I have 
therefore retained for it the more general name; and two young 
specimens and a half-grown one of the second species, and only a 
single young specimen of the third species ; the latter is so distinct, 
by the narrow form of its sternum, from the other two, that it might 
be referred to the genus Aromochelys if the pectoral plates were not 
triangular; it may be considered as the species passing towards 
that genus, and I should think that the adult animal must differ 
considerably from the common form of K. Pensylvanicum. 
AROMOCHELYS. 
The Musk Tortoise, or, as it is more commonly called, theStinkpot of 
North America, is easily distinguished from the other Kinosterna by 
the narrowness of the sternum and the humeral plates being square, 
like the pectoral one, instead of triangular, as they are in K. scor- 
poides and K.Pensylvanicum. For this reason I have proposed to 
divide them into a distinct group under the name of Aromochelys. 
I am the more inclined to do so, as theré are two most distinct 
species in the British Museum Collection, which have either been 
confounded together by the American naturalists, or have been most 
unaccountably overlooked. They may be thus defined :— 
1. AROMOCHELYS ODORATA. 
Head moderate, with two streaks from the nose, one above and 
the other under the eyes, to the side of the neck; the back oblong- 
convex, the vertebral line rather flattened; the gular plate small, 
triangular, the humeral plate rather oblique, shield brown, pufple- 
brown spotted. 
Holbrook, N. Amer. Herpet. t. 22. 
Hab. United States and Louisiana. 
2. AROMOCHELYS CARINATA. 
We have four specimens of this species in the Museum Collection. 
Cat. Tortoises B.M. t. 20 a. 
Head very large, black-dotted, without any lateral streaks; back 
oblong, very high, the vertebral line high and acutely keeled the 
whole length, shields grey-brown, spotted and lined with purple- 
brown; the gular plate very small, linear, transverse marginal, the 
humeral plate square, transverse, parallel to the pectoral plates. 
Hab. North America, Louisiana. 
There are two species of North American Tortoise which are re- 
ferred to the genus CuELypra, which are so differently organized 
that they are evidently the types of two verv distinct genera, which 
may be thus characterized :— 
