358 
OLDEST KNOWN PECCARY 
Perchoerus minor, Sp. Nov. 
The type of this species is specimen No. HC458, of the Cook 
Collections. 
An interesting condition is observed in the lower incisors. They 
are extremely crowded. The first and second are of about equal 
size, as indicated by their alveoli, and the third somewhat smaller. 
The alveoli for the first incisors are situated not only forward, 
but the full width of the teeth below and outside of the second 
incisors, which practically rest against the large canine. l¥ is 
situated outside and below It, on the lower front side of the 
canine, so that the three incisor roots form an equilateral triangle 
with each other. This is an extreme case of tooth crowding, 
without reduction. 
The canines are relatively large. The first premolar is small 
and single-rooted. The second premolar is evidently of fairly 
good size. Pt, is a simple primitive suilline tooth, with a single 
high thin, sharp crown, and vestigial heel. Pt, while considerably 
worn, had much the same construction, but widened posteriorly, 
with a broad heel against the first molar. Mt is considerably worn 
down, but is a very simple tooth. Mt is slightly larger, the four 
principal cusps, being arranged in essentially two low cross ridges, 
with little complicated enamel folding. Mt is long and narrow, 
and even more simple than Mt, and with a low, simple heel, or 
third lobe. 
This species has very brachyodont teeth, and is most like Leidy’s 
P. prohus, but is smaller, and more simple dentition. It may well 
be ancestral to that species. 
Measurements 
Length of dental series, It to Ms, inclusive.85 mm. 
Length of dental series, Pf to M?, inclusive./.56 mm. 
Depth of jaw below Mt .23 mm. 
Px, anteroposterior (approx) 4 mm.; Transverse. - .— 
P , anteroposterior (approx) 7 mm.; Transverse.— 
Pg, anteroposterior 9 mm.; Transverse. 4 mm. 
Px, anteroposterior 9 mm.; Transverse. 6 mm. 
Ml, anteroposterior U mm.: Transverse. 8 mm. 
Mg, anteroposterior 12 mm.; Transverse. 9 mm. 
Mg, anteroposterior 15 mm.; Transverse. 7 mm. 
