G. R. Wieland — Upper Cretaceous Turtles. 129 



(D) Thickness of Certain Bones of Carapace. 



Nuchal on median line 1 '6 cm 



" at ends.. _ _ 1'7 



2d Marginal at anterior end ." 2*1 



8th " " border _ 2'6 



8th " posterior " 1*4 



9th " " " __•'.._ 1*4 



Thickness 3d Marginal near inner border 0*6 



7th Pleural at distal end _. 06 



III. JPropleura Borealis sp. nov. — (Plate IX.) 

 A new species belonging to a different genus from Osteopygis, 

 but to the same family, the Propleuridae of Cope, is indicated 

 by Yale Specimen No. 778, from the old Cream Ridge Marl 

 Company's Pits, near Hornerstown, Monmouth Co., New Jersey. 

 This fine Upper Cretaceous turtle was received at the Yale 

 Museum in May, 1870. It consists in the nuchal ; 1st and 2d 

 neuralia; the 2d, 3rd, 5th, 6th and 7th right, and the 1st, 2d, 

 3rd, 5th and 6th left marginalia; the 1st and 2d, the 4th and 

 5th right pleuralia, with the 1st and 2d left pleuralia ; the hyo- 

 plastron and hypoplastron of the right side, with both xiphi- 

 plastra ; the left humerus, the pubis and ilium of the left side, 

 and both ischia. None of these bones are crushed, and they 

 are mostly little or not at all broken, and in a fine state of 

 preservation, as may be seen by reference to Plate IX, where 

 a photograph of all is given, the elements of the Carapace 

 being placed in their approximately natural position, with the 

 grooves marking the boundaries of the horn shields marked 

 in ivory black water color. The portions of the plastron pres- 

 ent are but very little broken, the view given being ventral, 

 just as if the parts were brought out from their natural position 

 beneath the carapace and to one side. Note that the antero- 

 exterior limb of the plastron so often broken away in dactylo- 

 sternal fossil plastra is entire. It projected into a pit at the 

 posterior end of the second marginal, in the manner also seen in 

 Osteopygis, and the interesting form of dactylate plastral union 

 described above for that genus is also repeated in the present 

 turtle. The humerus was broken in two, but the edges of 

 the fracture unite solidly. 



The pelvic elements unfortunately have their median sym- 

 physial borders broken away, but so much is present as to 

 abundantly warrant their restoration, as shown laid flat and 

 seen from the ventral side on Plate IX. 



Description and Comparison icith Osteopygis. 

 The form before us I shall, reviving Cope's genus, call 

 Projpleura borealis* The specific name may serve to lay 



* Extinct Batrachia, Keptilia, and Aves of North America. Trans. Amer. 

 Phil. Soc, vol. xiv, 1869, pages 138 et seq. 



Am. Jour. Sci.— Fourth Series, Yol. XVII, No. 98.— February, 1904. 

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