Q- 
Cope.] 94 [April 7, 
PRAOTHERIUM PALATINUM, Cope. 
Species nova. 
This rodent is represented by the palatal region of the cranium of one 
individual, with four superior molar teeth of each side in position. The 
latter diverge symmetrically, probably in consequence of pressure, But a 
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small part of the palatine surface is preserved. The normal number of 
teeth is uncertain, but the anterior tooth is known from its relation to 
the fragments of maxillary bone and perhaps zygomatic arch. It resem- 
bles the three molars which follow it. Behind the fourth no trace of 
tooth or bone could be found on exploring the matrix, though the latter 
was unbroken, hence it is possible, though not certain, that there were 
none. 
The genus differs from those of the @eomyinae of Baird, in the sim- 
plicity of the first molar. The wide palate and narrower zygoma, as 
well as the forms of the teeth, are those of the rabbits, but it differs from 
the two genera, Lepus and Lagomys, in the identity of structure of the 
first molar with the others, and the absence of an enamel band dividing 
the triturating surface of each of them. In some of the teeth a trace 
of the dividing lamina is visible, but does not appear to have been ele- 
vated into a crest of the grinding surfaces. 
In specific characters, this rodent differs from our rabbits in its small 
size, and in having the molars deeply longitudinally grooved on the inner 
face, instead of the outer. In worn teeth this groove is continued into 
the grinding surface of the crown, without interruption from the enclos- 
ing enamel. The form of this surface is then an oval, notched on the 
inner side, and rounded or slightly truncated on the outer. The palatine 
face is but partially preserved, and is considerably wider in proportion to 
the diameter of the tecth than in Lepus syloaticus. 
M. 
Length crown of four consecutive molars. ..........-.....00e0e. 0.0061 
Width ONG MOM stom teins, esos Mi in oe adh Ge 0021 
“, spalate between bases of.molang, oi.) c:c< fiesnia cise: 0100 
ScaLors, Cuy. 
The only remain certainly referable to this genus is ahumerus. As the 
