No. 374] FOSSIL MAMMALIA OF EUROPE. 117 
VII. 
LVote on the Structure of the Skull in Dichodon. 
The genus Dichodon has been recorded from the Eocene of 
Hordwell, England, at Egerkingen by Riitimeyer, and also is found 
in the Siderolithic du Mauremont. While at Paris in 1895, I had 
the opportunity of examining part of a skull from the Phosphorites, 
labeled Dacrytherium cayluxi. I at once noticed the modernization 
of this skull and the characters of the teeth, and immediately referred 
it to that little-known genus Dichodon of Owen. This genus has 
not, I believe, been recorded before from the Phosphorites of 
France. 
In Dichodon the fourth upper premolar is completely molariform : 
it resembles Agriochoerus in this respect somewhat, but in the latter 
this tooth has not developed the postero-internal cusp. _Dichodon 
stands unique among Artiodactyles in the complex structure of the 
last premolar. 
The facial part of the skull in Dichodon is high and strongly 
compressed. The anterior narial openings are not as terminal in 
position as in the Anoplotheroids, with a corresponding reduction 
in the nasal bones, obliquity and enlargement of the nares. As 
compared with Dacrytherium, there is no preorbital fossa, and the 
facial part of the skull in Dichodon is much more modernized than 
in the former genus. 
In comparison with modern selenodont Artiodactyla, the anterior 
portion of the skull in Dichodon closely resembles that of the 
Tylopoda and departs widely from the primitive type found in the 
Anoplotheres. 
With the exception of the closed dental series in Dichodon, this 
genus has apparently little near relationship to the Anoplotheres, 
but is a much higher type and more nearly related to the true 
Selenodonts. 
New ROCHELLE, N. Y., 
January 24, 1898. 
