692 The Tertiary Marsupialia, [July, 
The genus first discovered was the Plagiaulax of Owen, of 
which the typical species was found in the Purbeck bed of the 
Isle of Wight, England. It was made the subject of a memoir 
by Falconer. Ctenacodon was next discovered in the Jurassic of 
Wyoming by Marsh in 1879. In 1880 Dr. Lemoine discovered 
the first Tertiary representative of the family, and in 1882 named 
it Neoplagiaulax eocenus (Fig. 6). In November, 1881, 1 dè- 
scribed the first American Tertiary form, which was discovered in 
the Puerco beds of New Mexico, under the name of Ptilodus 
ian beds of Rew 
Fic, 6,—Neoplagiaulax eocenus Lemoine, from the Comey represented i 
France; fae ser -a rami and teeth of three individuals which i sal i, aol 
the letters 2,6 and c. Fi , 6, and c, much enlarg Ta de France, 18 
size, Fig. 4’’’, from above. From Lemoine, Bulletin de Soc. 
i ther wit 
Its presence in that formation, tog? of the 
d the near homotaxy New 
th those of 7 
mediævus (Fig. 8). 
various other associated types, proved ta , 
beds explored by Dr. Lemoine. near Reims Wi 
Mexico.! S gid remained? 
Up to this time the great Crese peri 
blank in the history of Mammalian lite, : r 
gists had eae the fresh-water beds of this period 
malian remains without success. Among them, 
1 See the NATURALIST, 1883, p. 870. 
