1881.] Geology and Paleontology. IOI7 
ITattan ANTHROPOLOGY.—Two original memoirs appear in the 
Archivio, Vol. x1, Fasc. 1: 
Maestrelli, Dr.— The exponent of vital capacity. 
Amadeé, Dr. Giuseppe—Numerical anomalies in the human dental system. 
GEOLOGY AND PALAONTOLOGY. 
A NEW TYPE OF PerissopaActyLa.—In a paper on the “homol- 
Ogies and origin of the molar teeth of the Mammalia Educabilia, 
published in March, 1874, I ventured the generalization that 
the primitive types of the Ungulata would be discovered to be 
characterized by the possession of five-toed plantigrade feet, 
and tubercular teeth. No Perissodactyle or Artiodactyle mam- 
mal was known at that time to possess such feet, nor was 
any Perissodactyle known to possess tubercular teeth. Shortly 
after advancing the above hypothesis, I discovered the foot struc- 
ture of Coryphodon, which is five-toed and plantigrade, but the 
teeth are not of the tubercular type. For this and allied genera, 
I defined a new order, the Amblypoda, and I have published the 
confident anticipation that genera would be discovered which 
should possess tubercular (bunodont) teeth. This prediction has 
not yet been realized. I now, however, record a discovery, which 
goes far towards satisfying the generalization first mentioned, 
and indicates that the realization of the prophecy respecting the 
Amblypoda, is only a question of time. 
In 1873,? I described from teeth alone, a genus under the name 
of Phenacodus, and although a good many specimens of the 
dentition have come into my possession since that date, I 
have never been able to assign the genus its true position in the 
mammalian class. The teeth resemble those of suilline Ungu- 
lates, but I have never had sufficient evidence to permit its refer- 
€nce to that group. Allied genera recently discovered by me, 
have been stated to have a hog-like dentition, but that their posi- 
tion could not be determined until the structure of the feet shall 
have been ascertained. 
In his recent explorations in the Wasatch Eocene of Wyoming, 
Mr. J. L. Wortman was fortunate enough to discover a nearly 
entire skeleton of a Phenacodus very near the typical P. primevus, 
which presents all the characters essential to a full determination 
of its place in the system. The unexpected result is, that this 
genus must be referred to the order Perissodactyla, and that, with 
its allies, it must form a special division of that order correspond- 
ing in the tubercular characters of its teeth with the bunodont or 
Suilline division of the Artiodactyla. In this character, however, 
there is a closer gradation than in the case of the Artiodactyla, 
1 Journal of the Academy of Natural Sciences Philadelphia. 
* Paleontological Bulletin No. 17, Oct., 1873, p. 3; also, Report G. M. Wheeler, 
U..S. Engineers Expl. W. 100 Mer., iv, p. 174—1877. 
VOL, XV.—No. XIT, ee 
