1892.] Geology and Paleontology. 763 
What is Lophiodon ?—Under this generic head the French, 
German and Swiss palwontologists have gathered a number of very 
diverse types of molar teeth. In the recent memoir of Prof. Rüti- 
meyer upon the Fauna of Egerkingen and his earlier memoir’ we find 
a series of beautiful figures in which the distinctive characters are 
very clearly brought out. They leave little doubt in my mind that 
the genus Lophiodon which has long been a sort of corral for all the 
fossil lophodont perissodactyls of Europe, in which the premolars are 
not like the molars, should be split up not only into a number of 
genera, but that these genera should be placed in a number of distinct 
families. This union of these forms under one genus, has been a 
natural result of the isolated condition in which the types have been 
found and the re-determination of these forms is only rendered possible 
by the complete series of upper and lower teeth which are now found 
in the Eocene, 
I am not at present in a position to attempt to review these forms 
thoroughly for I have not at hand the types, nor all the early litera- 
ture, nor the recent memoir of M. Filhol? I merely offer a few pre- 
liminary notes, availing myself of the admirable figures and descrip- 
tions of Riitimeyer. 
Turn first to Prof. Riitimeyer’s later volumes : 
The references are to his plates. Lophiodon annectens Riitimeyer, 
(Taf. I, fig. 12-13). These molars have the same characteristics as 
those of the primitive Tapirs, and bear a most striking resemblance to 
those of Isectolophus annectens from the American Eocene; this 
resemblance extends not only to the relations of the cusps and crests 
but to the development of a complete cingulum around the crown. 
Lophiodon cartieri Riitimeyer, (Taf. I, fig 12). The characteristics 
of this type (Fig. 10 b) are that the protoloph springs from the para- 
cone, the metaloph rises from a point slightly in front of the metacone, 
the paracone is conic while the metacone is slightly flattened upon the 
outer surface, the parastyle is low, the cingulum is feebly developed 
below the paracone. These are the characteristics of the series to 
which Heptodon Cope and Helaletes’ Marsh belong. The premolars 
1 Die Eocäne Siugethier Welt von Egerkingen,” Zurich, 1891. 
2« Eoczene Säugethiere aus dem Gebiet des Schweizerischen Jura,” 1862. 
' 3Filhol. “ Vertébrates fossiles d’Issel,”” Mém. Soc. Géol. de France. 1888. 
4See Osborn, “ Mammalia of the Uinta Formation,” Plate X, fig. 1. 
’Desmatotherium Scott is a synonym of Helaletes. See Bull. No. 3, E. M. 
Museum, 1883, Plate viii, fig. 3. 
