On Two new Species of Fossil Tortoises. 145 



XVIIT. — Note on Two new Species of Fossil Tortoises. By 

 C. W. Andrews, D.Sc, F.K.S. (British Museum, Natural 

 History). 



(rublished by permissiou of the Trustees of the British Museum.) 



The first of the two specimens wliich form the subject of tlie 

 ])reseut note is an internal cast of the shell of a rather large 

 Pleurodiran tortoise, with some of the carapace and plastron 

 still adhering to it. It is fiom the Upper Grecnsaud of 

 ^lelbury Down, near Shaftesbury, Dorset, and it is said to 

 have been used for some years for blocking a gate open, 

 a circumstance which proljably accounts for the broken 

 condition of the marginal portion of the shell. The speci- 

 men then passed into the collection of late j\Ir. John Kutter, 

 and was presented to the British Museum by Mr. Clarence 

 E. Rutter in 1915. 



Most of the carapace has been lost, and is represented only 

 by the natural cast of its inner surface. The parts preserved 

 are two or three costal bones on the right side, perhaps some 

 neurals, the })ygal, the supra-pygal or supra-pygals, and the 

 six posterior marginals much broken at the edges. Portions 

 of the posterior costals are present on the left side, and thei'e 

 are a few other adherent portions of bone of no importance. 



The plastron is, on the wJiole, beautifully preserved, only 

 the front of the anterior lobe being missing, the cpiplastrals, 

 the front of the entoi)lastral, and parts of the hyo-])lastral 

 being represented by the impressions of their upper surface 

 only. The bridge uniting the carapace and plastron is well 

 l)reservcd on the left side, but on the right most of it is 

 represented by tlie impressions of the bones only. The jjlates 

 of the carapace and plastron, together with the infilling mass 

 of matrix, probably give a pretty accurate idea of the true 

 form of the shell, which was strongly arched from side to 

 side and to a rather less degree from befoi'c backwards. 

 The length of the shell was approximately 580 mm. (tiie 

 front part of the cast is somewhat incomplete). The width 

 is roughly 170 mm. ; the height is a!)()ut :<!20 mm. ; the length 

 of the bridge is 225 mm. I'he plates all bear a strtnigly 

 developed ornament consisting of round or oval tuijcreles, 

 often Hat at the top and sometimes with a small depression 

 in the middle. They measure from one to four millimetres 

 across and arc most sti-onulv developed on the bridge and 

 the lateral portions of the plastron. In spite of this strong 

 sculpture horny scutes were present, at least on the plastron, 



Anil. c£; May. N. Hist. iSer. 'J. Vol. v. 10 



