80 Mr. R. Walker on Fossil Fishes of Dura Den. 



of the scales have fine thread-like sculptured lines extending 

 from the tubercles to the free margin ; these lines seldom ana- 

 stomose. 



Whether the preceding is a new species of Glyptolepis, or not, 

 would at present be rather premature to say. However this may 

 be, it has never been noticed before as occurring among the 

 Dura-Den fishes. 



There is another specimen in the museum which shows the 

 Glyptolepis crescentic structure of scale on some parts; it 

 appears to have been a fish of some size, perhaps 2 feet or more 

 in length, and is altogether different from H. Flemingii or the 

 fish last noticed. The specimen is laid nearly on the back ; the 

 head and a considerable portion of the anterior of the body are 

 wanting. The scales on the ventral surface and one of the sides 

 for about two or three inches above the lateral line are well ex- 

 posed, although not in a very good state of preservation. The 

 scales are about an inch, some of them rather more, in diameter, 

 and their external sculpture is more like the scales of H. gigan- 

 teus, Agass., than any other scales that I know : those on the 

 belly do not show the crescentic area of points ; whether the 

 points have never been there, or have been destroyed in lifting 

 the specimen, is not easy to determine ; but, on the flank and 

 above the lateral line, some of the scales exhibit the area of 

 points in front of the exposed sculpture very distinctly. From 

 what I recollect of the large fish found in Dura Den, last year, 

 by Dr. Anderson, I think it not unlikely that it and the large 

 specimen above noticed will yet be found to belong to the same 

 species. 



If I am not greatly mistaken, Dr. Anderson's specimen of last 

 year has the same form of tail as the Glyptolepis figured by 

 Miller in pi. 5 of the f Old Red Sandstone.' The finding of the 

 crescent of points on the large specimen has made me look still 

 more closely to the scales of H. Andersoni ; besides, it has often 

 appeared to me very probable that to whatever genus H. Fle- 

 mingii might be assigned, H. Andersoni, from its close resem- 

 blance, must also be assigned : in accordance with this view, I 

 have carefully looked over every specimen and fragment in the 

 museum (and, thanks to the labours of Dr. Heddle, they are not 

 few) ; but as yet I have entirely failed in finding the charac- 

 teristic crescent of points on the scales of any undoubted speci- 

 men of H. Andersoni. But the further consideration of this 

 and some other matters connected with these Dura-Den fossil 

 fishes must be left for another paper, wherein I will also direct 

 attention to some specimens of fishes either new to Dura Den or 

 at least not well known. 



