110 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.58. 



ably due to the accidental exclusion of a number of still existing 

 species that might be expected to occur there. 



It would be interesting to know exactly the geological age of the 

 deposits in which these species were found. The writer is informed 

 by Dr. E. W. Shaw, of the United States Geological Survey, who is- 

 familiar with the Pleistocene deposits about Alton, that there are at 

 that place deposits of loess of three or four Pleistocene stages; but 

 these have not yet been well differentiated, nor is it known exactly 

 where McAdams secured his specimens. Although he said that tha 

 loess there was rich in teeth and bones, he also added that a majority 

 of his specimens were found in one quarry. This would appear to 

 mean that they had come from the loess overlying some stone quarry 

 or possibly from that filling a crevice of the limestone. Doctor ShaAV 

 assures the writer that the nodules are those of the loess. ^ 



McAdams very probably had a catalogue of liis collection, for on 

 many of the specimens there is pasted a printed number. This cata- 

 logue, if there was one, has apparently been lost. 



MEGALONYX JEFFERSONII (Desmarest) . 



The genus Megaloyiyx is represented in the collection fi-om Alton 

 by a fragment, about 1 inch long, of a molar tooth (Cat. No. 8999). 

 After a comparison with Leidy's figures ^ it is evident that the tooth 

 was a lower right molar, probably the hindermost one. It does not 

 agree wholly with Leidy's three figures of this tooth,^ nor do these 

 figures resemble one another too closely. It is taken that the figure 

 last mentioned, made especially by Leidy, in order to be accurate, is 

 most to be relied on. From this figure it appears that the front and 

 rear faces were convex, while in the Alton specimen they are slightly 

 concave. The inner face of the latter tooth is more rounded than 

 shown in Leidy's figures. The tooth, too, is thinner from front to 

 rear (16 mm.) than in the one described by Leidy (8.5 lines=:l7.T 

 mm.). The pulp cavity is shown at one end of the fragment and is- 

 filled apparently by fine sand and loess. 



EQUUS, sp. indet. 



In the Alton collection, with the number 25, is a portion of an 

 'ncisor of a horse (Cat. No. 9000). It has no loess attached to it, but 



1 Since this paper was put into tj'pe Mr. Morris M. Leighton, of tlie State Geological 

 Survey of Illinois has informed the writer of investigations made by him recently under 

 the direction of the head of the survey, Dr. F. W. DeWolf. Mr. Leighton had the 

 good fortune to And Mr. John D. McAdams, a son of the collector of the fossils, who 

 pointed out to him the quarry in which his father had collected most of the specimens. 

 These occurred at the base of the loess, but apparently in the upper part of the drift*. 

 While the exact age of the deposit is somewhat in doubt, Mr. Leighton regards it as 

 belonging probably to the Sangamon. 



2 Smiths. Contr. KnowL, vol. 7, 1855, art. 5. 



s Idem, pi. 5 ; pi. 6, fig. 11 ; and pi. 16, fig. 17. 



