206 NORTHERN ZOOLOGY. 
[65.] 1. Dietosroma? sutsrvorum. (Rich.) Camas-Rat. 
Genus. Diplostoma. RaFrinEsQuE-SmMaLtTz? (DEesmarest, Mamm.) 
Puate xvi B. 
There is a specimen of a quadruped in the Hudson’s Bay Museum, which 
Mr. David Douglas informs me is the animal known on the banks of the Columbia 
by the name of the Camas-rat, because the bulbous root of the Quamash or Camas 
plant (Scilla esculenta) forms its favourite food. The scull is wanting, and the 
animal, therefore, cannot be with certainty referred to a genus, but the form of 
its exterior cheek-pouches leads me to think that it may belong to the diplostoma of 
M. Rafinesque-Smaltz. There is, however, a discrepancy in the number of its 
toes and in the presence of a tail, which, if M. Rafinesque’s specimen was perfect,. 
is decisive against this arrangement. The characters of the genus diplostoma, as 
quoted by M. Desmarest, are as follows :— 
« Diplostoma (Am. Month. Mag. 1817.)—Mouth double ; the exterior one 
formed by two great pouches, which extend as far back as the shoulders, and 
meet before the incisors, all of which are furrowed; four molar teeth of a side 
in each jaw ; body cylindrical ; neither tail nor ears; eyes hid by the fur; four 
toes on each foot. This genus is nearly allied to that of. the .mole-rat, but differs 
in its cheek-pouches, and in the number of its toes. Two species were discovered 
by Bradbury on the Missouri. They live beneath the surface of the earth and eat 
roots. The early French travellers named them gauffres.” 
DESCRIPTION. 
Form.—Body like that of a great mole, with a head that appears large and clumsy owing 
to the swelling out of the cheek-pouches. The nose being margined by a slight prolongation 
of the superior edge of the cheek-pouch appears flat and broad, but its tip and nostrils are 
comparatively small ; it does not project in the least beyond the plane of the incisors, 
The incisors are entirely exserted, are stronger than those of the musk-rat, and have three 
convex sides. The anterior side is the broadest, is without grooves, and has a yellowish 
colour. ‘The upper incisors have even cutting edges, and project forwards and downwards 
immediately from under the nostrils, instead of standing out from a cleft in the upper lip. 
The lower ones are linear, with round tips, and project nine lines above their sockets, being 
longer than the upper ones. The true mouth is a vertical slit, nearly an inch long, situated 
aS 
