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355 



received from the Aftonian gravels of southwestern Iowa. There are 

 superior and inferior molars of Equus complicatus and a fine claw of 

 Megalonyx from gravel pits at Sioux City. From Missouri Valley there 

 are a sixth molar of mastodon, a superior grinder of Equus scotti, and a 

 second inferior molar of Camelus. A pit at Logan has furnished a fine 

 molar of Eleplias columbi, while from Turin there has heen received a 

 large collection which includes a sixth molar of mastodon, three meta- 

 tarsals and three first phalanges of Equus, two phalanges of Camelus, a 

 phalanx of either elephant or mastodon, and a great number of imperfect 

 bones not yet identified. 



The probable presence of Megalonyx as a member of the Aftonian 

 fauna is noted in the body of the paper ; the only point concerning which 

 there might be possible doubt is the age of the beds in which the specimen 

 collected by Todd was found; the claw now in hand from Sioux City 

 places the matter of an Aftonian Megalonyx beyond question. 



We now have remains of Aftonian camels from three localities— Turin, 

 Pisgah, and Missouri Valley. 



Two of the equine metatarsals and two of the phalanges from Turin are 

 decidedly* larger than the corresponding bones from the modern horse. 

 One of these large cannon bones is complete and measures 30.5 centi- 

 meters in length, while a metatarsal of a fair sized modern horse, with 

 which it is compared, measures but 27 centimeters. Other measurements 

 show corresponding differences between the fossil and the domestic spe- 

 cies. One of the teeth noted in the paper (figures 2, 4, plate 18) agrees 

 in size with Equus pacificus Leidy. It is larger than the teeth of Equus 

 scotti recorded by Gidley. Tt may be possible that this large tooth and 

 these large cannon bones belong to a species larger than Equus scotti; 

 but on the other hand it is possible that individuals varied, and that some 

 of the animals belonging to the species Equus scotti may have exceeded 

 "the size of the largest western pony/' The solution of some of these 

 questions must await additional evidence. 



Probably the most important of the recent additions to our knowledge 

 of the Aftonian mammals comes in the form of two molars of Mammut 

 mirificum, or Mastodon mirificus Leidy. These teeth were found in 

 Aftonian gravel which was penetrated in digging a farm well near Akron, 

 in Plymouth county, Iowa. They are well worn down by use, and show 

 the characteristic features of this remarkable species unusually well (plate 

 27) . The teeth are the last of the upper molar series — one right, one left. 

 With them were found portions of the tusks and a large number of pieces 

 of the cavernous cranial bones. A part of the maxillary still adheres to 

 the left molar. The left tooth measures 8% inches long and 3*4 inches 



