THE ANiNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



[FOURTH SERIES.] 



No. 119. NOVEMBER 1877. 



XL VII. — On Pteroplax cornuta, H. <Ss A, 

 Bj Thomas Atthey. 



[Plates xn. & xin.] 



In the ' Annals and Magazine of Natural History/ ser. 4, vol. i. 

 1868, appeared " Notes on the Remains of some Reptiles and 

 Fishes from the Shales of the Northumberland Coal-field," hj 

 my late friend Mr. Albany Hancock and myself. 



In those notes were described two crania of Pteroplax 

 cornuta, the upper surface of the smaller one being figured 

 of about two thirds the natural size (pi. xv. fig. 1) ; sub- 

 sequently the matrix having been more carefully removed 

 from the surfaces of both crania, two well-defined sutures on 

 each have been brought to light, and are seen to divide the 

 bone which had been named postfrontal into three distinct 

 parts — namely, the postfrontal proper, the postorbital, and 

 the squamous. 



In the present communication I propose to describe and 

 figure, of the natural size, the upper surface of the smaller 

 and the under surface of the larger cranium, also some ribs 

 and vertebra?, three bones of an extremity, and some scutes, 

 all of which mast probably belonged to the same amphibian. 



The 'crania have undergone immense pressure and are con- 

 sequently much flattened. Together with the other bones they 

 arc from the black shale, a stratum varying from 3 to 4 inches 

 in thickness, overlying the Low Main seam of coal at News- 

 ham Colliery, near Blyth, Northumberland. 



A nn. & Mag. N. Hist. Ser. 4. Vol. xx. 26 



