8 



BRITISH FOSSILS. 



" found in them and this supposition is, he states, confirmed by 

 the similarity of the upper and lower jaws, and teeth. Behind the 

 jugular plates, and applied to their hinder edges, Professor Pander 

 finds two others, which meet in the middle line, and resemble those 

 which lie upon the under surface of the pectoral arch in Polypterus. 



The scales are, in general, rounded, sometimes circular, sometimes 

 oval, sometimes more or less quadrate, by reason of the less rounding 

 off of their angles. They overlap in different degrees, and their 

 external sculpture is different in difi'erent parts of the body, whence 

 arises such an amount of unlikeness, that different species might 

 readily be founded on scales from different regions. 



The sculptured surface presents two divisions, one, more anterior, 

 exhibits small tubercles with projecting points, which are convex 

 posteriorly, concave anteriorly, and are disposed in regular series 

 converging towards a central point, which, however, they do not 

 reach. 



The posterior segment is covered with wavy longitudinal costse, 

 which gradually diminish in thickness from the anterior towards 

 the posterior edge. 



Professor Pander gives a figure of this peculiar sculpture, a 

 woodcut copy of which I subjoin, and side by side with it a careful 

 drawing of the sculpture of the scale of a Glyptolepis from Wick, in 

 an even better state of preservation. 



Fig. 6 The two left hand figures represent the scale from Wick of the natural size and 

 its sculpture magnified ; the right hand figure is copied from Pander's Monograph. 



