PEOr. H. a. SEELEY ON PSEPflOPHORFS POLYGONFS. 407 



about thirteen Vienna inches long, and fifteen at its greatest breadth. 

 Numerous bony plates are said to be scattered through the mass of 

 the sandstone, besides other bone-fragments ; and Yon Hauer considers 

 that there is a second shield, which lies parallel to the first, and 

 under it, at an interval of scarcely half an inch. YonMeyer had made 

 another short note on this fossil in the ' Berichte iiber die Mitthei- 

 lungen von Preunden der Naturwissenschaften in Wien ' for 1861 

 (p. 3), which Yon Hauer well epitomizes by saying that although 

 the animal had originally been regarded by Yon Meyer as belonging 

 to the Armadillo family, he subsequently showed the striking re- 

 semblance of the carapace from Neudiirfl with one from the Zeugio- 

 dont Limestone of North America, which MuUer had figured and 

 compared with the dorsal shield of Dermatoclielys in his work on Zeu- 

 glodon. But, beyond drawing attention to its resemblance to the 

 Psephoderma alpina from the Upper Trias, and pointing out some re- 

 semblances which that genus presents to the crocodilian type of 

 armour. Yon Hauer expresses no opinion on the systematic position 

 of the genus. Finally Dr. Th. Euchs, in notes on his travels in Itdly, 

 printed in the ' Yerhandlungen der k.-k. geologischen E-eichsanstalt' 

 for 1874 (p. 220), remarks that in the zoological department of the 

 Museum at Plorence he saw the remarkable shield of SpJiargis 

 co7'iacea ; and adds, " the fidl resemblance to our Pseplwphorus is 

 so evident that I cannot imagine that any one who had seen the 

 two could remain a moment in doubt^on this matter." Yon Meyer 

 appears to have inclined towards the Chelonian hypothesis, in conse- 

 quence of Miiller's account of the Spliargis in the Zoological Museum- 

 in Padua ; and it only remained for Fuchs to confirm the accuracy of 

 this interpretation. 



The slab of hard sandstone in which the specimen is preserved is 

 46 centimetres long, and about 41 centimetres wide. It only shows 

 a small portion of the shield, which originally covered the back of 

 the animal, the principal part preserved being 33 centimetres long 

 and 35 centimetres wide. It is divided into two portions by an 

 elevated longitudinal median keel or crest. The lateral parts are 

 inclined to each other at an angle of about 155 degrees. The keel 

 does not appear to be quite straight ; and it would be difficult to 

 assert positively that it occupied a lateral position in the body, 

 though this probably was the case. The keel is rounded, and formed 

 by a single row of polygonal plates, portions of eleven of which are 

 preserved ; nine occupy a length of 28 centimetres. Nothing could 

 be more remarkable than the extreme irregularity of size and form 

 of the ossicles which make up the lateral portions of the carapace. 

 Some small ossicles are nearly circular, others ovate, triangular, sub- 

 quadrate, but mostly of irregular forms with five, six, or more sides, 

 which are sometimes convex, sometimes concave, and often with 

 sharp angles at the points where they join the neighbouring little 

 plates. Occasionally a minute plate occurs which is hardly a centi- 

 metre in diameter ; but most of the plates are from two centimetres 

 and a quarter to two and a half centimetres in diameter. Their 

 substance is very dense, almost like the palatal teeth of Plethodus or 



