No.1747. DESCRIPTIONS OF NEW FOSSIL TURTLES HAY. 



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runs backward from the inguinal notch. Fig. 10 represents the 

 outline of the anterior pari of the nuchal bone, while fig. II shows 

 the section of the bone where it joined the firs! peripheral. From 

 one extremity of the bone to the other, at the anterior holder and in 

 a straight line, the distance is 87 mm. The greatest thickness of the 

 bone is at the midline and amounts to 86 mm. The nuchal scute is 

 32 mm. long, 5 mm. wide in front, and II nun. behind. On the 



Figs. 8, 9.— Basilemys piusclara. x*. 8. median section of front of plastron; ent, entoplas- 

 tron; epi, epiplastron; 9, section of free border of xiphiplastron 40 mm. behind hypoplastron. 



anteroinferior surface of the bone this nuchal scute broadens to a 

 width of 25 mm. where it joined the soft skin. 



There is present the thickened border of one free peripheral, prob- 

 ably one of the hinder ones. It is 90 mm. long at the free edge and 

 has a maximum thickness of 26 mm. On the inferior surface the 

 sculpture rises to a height of 45 mm. The bone is crossed by a 

 sulcus between two marginal scutes. The sulci found on the various 

 bones present great contrasts. Sometimes they are extremely narrow 



Pigs, lo, 11. — B lsilemys prjeclara. x '». 10, uppersurface of front of nuch w.; ll, section across 



NUCHAL NEAR UNION WITH FIRST PERIPHERAL. 



and shallow and can hardly be followed over the pits and ridges, 

 while others are broad and sometimes deeply impressed. The bones 

 are sculptured as in the two other species of the genus that have been 

 mentioned. The ornamentation consists of pits separated by sharp 

 ridges, and the latter rise into points at the boundary between three 

 pits. On some parts of the carapace the pits are shallow, resembling 

 those of some Trionychidse. The lower surface of some of the plas- 

 tral bones are rough but often devoid of the pits. 



