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Jrom the Tertiary Formation. 41 
Platygonus striatus, sp. nov. 
A third Suilline species, nearly related apparently to the 
last, and quite equaling it in size, is indicated by portions of 
two lower jaws, with a few of the anterior teeth, collected by 
our party in the Phocene strata of Northern Nebraska. In one 
of the specimens, the second left premolar is well preserved, and 
characteristic. It has the same general composition as the cor- 
responding tooth in Platygonus compressus, but, in addition to 
its much larger size, it is proportionally broader, and has the 
basal ridge in front less developed. The posterior basal ridge, 
moreover, is expanded into two rudimentary tubercles. The 
enamel is marked by delicate irregular strize, mostly parallel with 
the base of the crown, and to this ornamentation the specific 
name tfefers. 
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Measurements. 
Length of portion of left lower jaw containing first four 
teeth ere 
te wkend - lines. 
Length of same, with first three teeth,._.-..-.--.---- Re eae: 
Antero-posterior diameter of second lower premolar,.. 62 “ 
Transverse diameter of same,.._...-------- ---------- ig Bae 
_ The above specimens were found by the writer, in July last, 
in the Pliocene sands, near the head-waters of the Loup Fork 
River, Nebraska. 
Platygonus ? Condoni, sp. nov. 
tially divided into three tubercles. The enamel is smooth, and 
there is no basal ridge on the sides of the teeth preserved. 
Length of jaw enclosing last three upper molars, --- --- 27 lines 
Antero-posterior extent of last molar, ----- Gaccsocs ss 12 Z 
Transve iameter of same, through anterior lobes,-.- 7° = 
_ This species is named for Rev. Thomas Condon, who discov- 
ered the specimen described, inthe Pliocene beds of Oregon. 
