F. B. Loomis — Turtles from the Upper Harrison Beds. 17 



Art. IV. — Turtles from the Upper Harrison Beds; by 



F. B. Loomis. 



In spite of the considerable activity in collecting in the 

 Harrison Beds in the vicinity of Agate, Nebraska, but three 

 turtles have been described, and these are all from the upper 

 beds. Two, Testudo edae and T. hollandi, are known from 

 nearly complete shells, while T. arenivaga is based on simply 

 the pygal and eleventh peripheral plate. During the explora- 

 tions of the Amherst party in the country between the Muddy 

 Creek and Agate, Neb., it was their good fortune to lind in the 

 Upper Harrison beds, among other turtle remains, most of the 

 skeleton of T arenivaga and two new Testudinge, one of 

 which is accompanied by an almost complete skeleton. 



The entire lack of remains of aquatic forms has always 

 struck the writer as very suggestive that these beds were 

 deposited largely, at least, by winds ; and of all the groups of 

 land animals which are most likely to offer aquatic representa- 

 tives the turtles are most favorable ; but, while five species are 

 now known, and their remains are by no means rare, every 

 representative is an upland form, and so far all belonging to 

 the genus Testudo. Among the mammals also the remains are 

 all terrestrial forms. Then from the structure of the deposits, 

 the irregular character of the bedding, the presence of occa- 

 sional large pebbles, and the intermingling of very fine 

 material with coarser sand, all point in the same direction, 

 namely wind deposition. 



The following paragraphs are descriptive of three turtles ; 

 of which T. arenivaga belongs with the large land tortoises 

 characteristic of the Miocene of western America, while 

 T orevisterna and T. undabuna are quite aberrant from the 

 typical forms of the epoch. The latter two were found on 

 Muddy Creek in beds which also contained Merychyus 

 minimus Peterson in abundance, and are, therefore, assigned 

 by the writer to the Upper Harrison horizon. 



Testudo arenivaga Hay. 



Testudo arenivaga Hay, Ann. Carnegie Mus., IV, 1906, p. 16. 

 Testudo arenivaga Hay, Fossil Turtles of N. Amer., Carnegie Institute, 

 1908, p. 430. 



The type of this large species is JSTo. 1509 in the Carnegie 

 Museum, and consists of the pygal and right eleventh peri- 

 pheral plate, found in the Upper Harrison beds, "two miles 

 north of Agate Spring Quarry." Within a mile or two of the 

 above the Amherst party found a second specimen (No. 2165 



Am. Jour Sci.— Fourth Series, Vol. XXVIII, No. 163.— July, 1909. 



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