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1876.] Geography and Exploration. 379 
GEOLOGY AND PALMONTOLOGY. 
Tue TÆNIODONTA, A New Group or Eocene Mammars.— Ata 
recent meeting of the Academy of Natural Sciences of Philadelphia, Pro- 
fessor Cope described the character of some mammalia from the Eocene 
deposits of New Mexico, obtained by him during the Wheeler Expedition 
of 1874, which he regarded as allied to the Jnsectivora. The feet are 
armed with compressed claws. The dental characters are seen first in 
the supposed superior incisors. Unfortunately they have not yet been 
found in place in the cranium, but their association with a rodent type of 
inferior incisors, which have been found in place in the mandible, con- 
fines us to the alternative choice between superior incisors and canines. 
From the small size or absence of inferior canines a similar character 
may be inferred for the superior canines. . 
The superior incisors present two bands of enamel, an anterior and 
a posterior. They are compressed in form, the sides presenting a sur- 
face of dentine or cementum. Attrition produces a truncate or slightly 
concave extremity. The inferior incisors are rodent-like. 
Two families represented this suborder in the Eocene period in New 
Mexico. The first, or Ectoganide, possessed molar teeth with several 
roots ; in the Calamodontida, each molar has a simple conic fang. But 
one genus of each family is known. In both the enamel of the molars 
1s principally a band on the outer side of the crown; the deficiency is 
supplied in Calamodon by a deposit of cementum which invests the 
molar and superior incisor teeth, covering the crowns excepting where 
the enamel bands are present. The latter investment is so much thinner 
that the cementum forms a raised border all round at the point of junc- 
tion of the two substances. The general structure of Calamodon affords 
some points of approximation to the Edentata, which indicate that the 
Teniodonta partially fill the interval between that order and the Eden- 
tata presented by the existing fauna. 
Professor Cope also pointed out the close resemblance between the 
mandibular dentition of the contemporary Eocene genus Esthonyx and 
the existing Erinaceus, and stated that Anchippodus and allies chiefly 
differ from Esthonyz in the persistent growth of the incisor teeth. 
GEOGRAPHY AND EXPLORATION. 
Peruvian Grocrarny.— The publication of the preliminary volume 
of Don Antonio Raimondi’s great work, El Peru, will be, says a writer In 
the Geographical Magazine, an epoch in the history of Peruvian geo- 
graphical research. ‘This accomplished and indefatigable geographer 
and naturalist had traveled over every part of the republic, on a fixed 
Plan, during a space of nineteen years, diligently collecting materials be- 
i See On the Su posed Carnivora of the Eocene of the Rocky Mountains, Proceed- 
"BS of the Philadelphia Academy of Natural Sciences, December, 1875. 
