114 G. R. Wieland — Upper Cretaceous Turtles. 



figure, by a distinct narrowing in the anterior region, so that 

 the greatest breadth is seen two-thirds of the entire length 

 back. A very slight double curvature of the outer border also 

 appears to be present, as shown in Plate 1. It is found, too, 

 that there is less flattening of the carapace than is suggested in 

 figure 1, the curvature rather closely approaching that of Der- 

 matemys mawii* The unusual heavy furrow marking the 

 boundary between the first vertebral and first pleural, also 

 between these two elements and the nuchal and first four 

 marginal horn shields, is shown in the orignal figure, as well 

 as in the additional outline figure (Plate 1) drawn by the 

 writer from the remounted specimen. In the latter figure the 

 sutures are indicated by the serrate lines, and the boundaries 

 of the horn shields by a triple line. With the prominent 

 exception just noted, the other boundaries of the horn shields, 

 though distinct, are indicated by a narrow and shallow groove 

 only. The finely punctate sculpturing of the surface of the 

 carapace is fairly well shown in Plate II, reproduced from a 

 photograph. The punctations are of sub-triangular outline. 

 They appear nearly as if made by the slightly blunted corner 

 of a chisel blade, and approach regularity in their distribution. 

 The plastron, like the carapace, has a punctate surface. 

 The preservation is also exquisite, and the complete trace of 

 all the bony plates and horn shields may be accurately deter- 

 mined, as shown in my outline drawing, Plate III. 



Synopsis of the Characters of Adoeus. 



Carapace.— Of rather elongate sub-elliptical outline, and 

 composed of 48 bony plates with the grooves marking the 

 borders of the 38 horn shields distinct, as follows : — 



(a) Bony Plates: Marginals 11 pairs, large and heavy, the 

 inner borders uniting solidly with other elements by suture ; 

 nuchal large, of sub-pentagonal outline and without nether or 

 costiform processes ; pygal as large as nuchal, and of sub- 

 octagonal shape, its boundaries being the 9th neural, 8th pleu- 

 rals, 11th pair of marginals, and the intervening pygal mar- 

 ginal ; pygal marginal large and of sub-quadrilateral form ; 

 pleurals 8, the 2d-8th being without rib capitulse, and the 7th 

 and 8th meeting on the median line; neurals, 7 in all, — there 

 being no true 7th and 8th, the trite 9th following the interim 

 formed by the median junction of the 7th and 8th pleurals. 



(b) Horn Shields : A diminutive nuchal and 12 paired mar- 

 ginals, the first four pairs being intermediate in width between 

 the same elements in Osteopygis and Chelydra, and the others 

 of large area rising high on the carapace / 5 vertebralia ; 4 pairs 



* Table XXI, Gray's Catalogue of Shield Reptiles, Part I. London, 1855. 



