90 [April, 



structed like those of the Flares. The first inferior rmlar is bi-lobed and not tri- 

 lobed as in the bitter The number of incisors cannot be ascertained in the 

 specimens. Those inferior have miuh longer roots than ia the Hares, as they 

 extend buck beneath the molar teeth. 



Length of superior molar series 4^ lines, G lines, 7 lines. 



Length of inferior molar a Ties 5 lines, 8 lines. 



Found in the Mauvaises Terres of Nebraska. 



T. EuMYS ELEQANS, Leidj. 



The genus and species are founded upon a fragment of the lower jaw, con- 

 taining the middle molar, and the fangs of two others. The estimated size of 

 the skull would be about that of the Rat, (^Mus decumanus), and the animal also 

 appears to belong to the same family. The molar series of the lower jaw consists 

 of three teeth, and they have exserted crowns inserted by distinct roots. 

 Length of lower molar series, ----- 3| lines. 

 Depth of lower jaw below middle molar, - - - 2| lines. 

 Discovered in the Mauvaises Terres of Nebraska. 



CARNIVORA. 



8. Amphicyon ? GRACILIS, Leidy. 



A small species of this genus is probably indicated by a specimen in Dr. 

 Hayden's collection, consisting of a fragment of the lower jaw containing two 

 teeth, of which one corresponds in form with the antepenultimate molar of 

 Amphicyon m ijor DeBl. or of A. veUia Leidy, and the other, being the tooth in 

 advance, has nearly the same form as the corresponding tooth in the wolf. The 

 length of the crown of the antepenultimate tooth is 2| lines, its breadth 4J lines; 

 and the depth of the lower jaw is 5 lines. 



The specimen was discovered by Dr. Hayden, in association with remains of 

 AnchUherium, Ilyopotamus, Hyaenodon, etc. in Nebraska. 



Notice of the remains of a species of Seal, from the Post-pliocene deposit of the Ottawa 



River. 



By Joseph Leidy, M. D. 



E. Billings, Esq., of Ottawa, West Canada, recently sent to the Academy, for 

 the inspection of its members and for description, a specimen consisting of a 

 slab or portion of a concretion of indurated clay, containing sofne imbedded 

 bones, which Mr. B. observes, in a letter accompanying the specimen, " appear 

 to him to be those of the extremities of a small animal of aquatic habit." Mr. 

 B. further states, " the specimen was discovered by Mr. Peter McArthur, in a 

 bed of bin } clay containing boulders and marine shells and fishes. The locality 

 is in the township of Gloucester, county of Carleton, Canada West, about nine 

 miles east of the city of Ottawa. From this city the river Ottawa runs easterly 

 for about sixty miles, in a channel excavated through a bed of the glacial drift, 

 composed in some places of clay, and in others of sand, gravel and boulders. 

 Where the specimen was discovered, the bank of the river is of clay about thirty 

 feet high, at the time of low water. The water washes out of the bank nume- 

 rous nodules of the clay, which are consolidated into a pretty hard kind of stone. 

 Many of these nodules, when split open, are found to coatain shells, or the skele- 

 tons of fishes, often beautifully preserved. The species of shells found up to the 

 present time are Tellina grocniandica, Mylihis edulis, Saxicava rugosa, and a small 

 rostrated one like a Lcda ; and of fishes two species, 3Iollottis viUosus and Cyclop- 

 teris lumpiis. They also contain leaves of trees, broken twigs and grass, showing 

 that there was land at no great distance. There is a ridge of low metamorphic 

 hills on the north shore of the river, extending for a great distance parallel with 

 and near the stream. On the soath side the country is level, and underlaid with 

 lower Silurian rocks, Utica slate, Trenton, Black River, Bird's-eye and Chazy 

 limestones, with here and there a strip of the lower rocks brought up to the 



